Walls. There is none. Remove all sheet rock interior walls insulate and replace the sheet rock. All above grade. Haven't gotten to the crawl space yet. As long as crawl space was mentioned what is the best way for doing that(insulation)?
Insulate with what? It makes a difference!
If the sheet rock is in good shape it's better and maybe even cheaper to leave it in place and have a pro drill a single ~2.25" hole in each stud bay to "dense pack" it with blown cellulose (3.0-3.5lbs per cubic foot is fine for a TN climate- 3.5-4lbs might be necessary in colder wetter climes), using a "borate only, sulfate-free" version that only uses borates, not sulfates as fire retardent. Borates kill off the gut-flora of ants, making it impossible for them to digest food and they die of starvation. But since ants as a species will usually cannibalize the weak, they end up distributing the borates to the nest, often killing off the colony.
If the sheet rock has had it and you're gutting it anyway, take the time to caulk every stud to the sheathing, and foam-seal all plumbing and electrical penetrations, even between studs. Don't forget to caulk the bottom plate to the subfloor, and the seam between the doubled-up top plates etc. (Use an "acoustic sealant" type caulk, which stays flexible for many decades.) By making each cavity air-tight, you improve the thermal performance of any fiber insulation, and make the ants work harder for their super-highway systems.
At that point you can decide what to put in there. Open cell polyurethane foam is more air-tight, but ants will tunnel through it readily. Wet-sprayed cellulose is about the same or slightly cheaper installed price in my neighborhood, and has the anti-insect borate fire retardents. For the DIYer, R15 rock wool batts (Roxul is now carried by the orange & blue box stores) are high performance when installed perfectly, completely fireproof and dense enough to limit convective and infiltration losses from any incidental air leakage. But they're substantially more expensive than the loss-leader R13 fiberglass rolls from box store outlets.
If you go with a batt solution, take care to tuck every edge & corner into the stud bay as you install it, then tug it back out to where it's just slightly proud of the stud, to ensure it fills in completely, with no performance-robbing gaps, compressions, and convective bypass paths. Split them over wiring runs rather than tucking them, and trim carefully around obstructions like electrical boxes, plumbing etc for the snuggest fit you can get. Rock wool batts trim pretty easily with a bread knife or even a dull hacksaw blade, but there are also purpose-made batt knives well worth the nominal cost if you're doing a lot of it.
If you're gutting it, take care to tuck shredded batts densely around the window & door framing leaving about 1/2"-3/4" of space in the tight places to air-seal it with a low-expansion "windows & doors" can-foam. Be sure to pack the fiber in so that it's a bit denser than the installed batt would be. An R13 batt at it's full loft runs ~R3.7/inch, but compressed it will run R4-R4.2/inch. The key is to not leave any gaps, then make it air-tight with the foam.
Before insulating it's also good to seal all the holes/seams/wiring penetrations of the electrical boxes with fire-stop can foam (which is what you should be using on wiring penetrations of the studs too.) Then when you put the new sheet rock up you can caulk the edges of the sheet rock to the framing, and caulk the cut-outs to the wiring boxes too. Air-seal detailing seems tedious at first, but it's by far the cheapest thermal performance improvement you can buy! If you go with open cell spray foam, most of the air sealing details become somewhat moot, but DO caulk the bottom plate to the subfloor, and the seam between the top-plates, which would not be touched by the foam in the cavity.
To insulate the crawlspace there are three points of consideration- the bandjoist/foundation sill, the crawlspace walls, and the crawlspace floor.
If you have any history of seepage/flooding moisture down there it's probably worth digging in a perimeter drain using perforated pipe to a sump that can be pumped if/when necessary, backfilled with pea-gravel. Then put down a 6-10 mil poly vapor barrier on the floor, lap any seams by a foot or so and seal the seams with duct mastic. (Alternatively you could use EPDM roofing membrane, which is far more rugged than poly.) have it lap up the walls 8-12" and mastic seal it to the foundation wall.
There's a long term economic rationale for putting down 1" (R4) of rigid EPS foam on the floor in your location, even if you're heating with natural gas or heat pumps. If you're heating with propane, resistance electricity or oil, there's a good rationale for R8 (2") EPS. But depending on local codes you may then be required to put down an ignition barrier such as a 1-2" non-structural concrete "rat slab" directly on top of the foam, but you may want to do that anyway, as insect & rodent deterrence. (Rat slabs in crawlspaces are required by code in some states even without foam insulation on the floor, but SFAIK not in TN.)
To insulate a poured concrete or block crawlspace foundation it's best to use either 2" of closed cell spray foam (about $2 per square foot, installed), or 2.5-3" of EPS or 2" of polyiso (foil-faced is fine if there is adequate above grade exposure on the exterior for ground moisture to dry to the outdoors rather than wicking up to the foundation sill, otherwise stick with unfaced EPS.) If there is any question of termites in your neighborhood, it's good to slip in thin copper flashing lapping over the top of the wall-foam, extending to the foundation sill, to reliably block them from tunneling undetected through the foam to the wood. To install the foam, tack it in place with blobs of foam-board construction adhesive. It comes in the same types of tubes as other construction adhesive, but it's solvents won't degrade the foam the way standard construction adhesive does. Then use 1x furring to secure it to the foundation with TapCons 16-24" o.c., which also gives you something to hang half-inch sheet rock to as a code-required ignition barrier. R8 onwould be the absolute minimum, in a TN climate, but even R15 still makes sense if you're heating with propane. But R15 EPS is 4" thick, which makes for some fairly long and hard to find masonry screws, so you'd be looking at 2.5" of polyiso instead.
On the foam, if EPS, duct mastic sealing the seams is the right way to go, if foil-faced iso, 2" FSK tape works. Doing it in two layers with the seams lapped by a foot or more is more air-tight than a single layer, but using ship-lap edges or sealing the seams with can-foam is reasonable too, and often easier.
For the foundation sill and band joists it's sometimes cheaper & easier to let a pro hit it with 3-4" of open cell foam, which air seals and insulates. Otherwise, caulk the band joist to the subfloor and foundation sill, and use can-foam to seal the foundation sill to the foundation, then cut'n'cobble in rigid foam, sealing the seams and edges with can-foam. If you have enough headroom to work in there it goes quicker than you might think, but be sure to provide some ventilation air while working with can-foam in a confined space- the blowing agents aren't something you want to be breathing in high concentrations.
Block off any vents to the outdoors and insulate/seal them. If local codes require that there be operable vents in all crawlspaces (often the case in flood zones), make up hatches or doors that seal snugly with weather stripping. In a TN climate any air leakage into a crawlspace adds more ant-friendly moisture than it ever purges. If you make it air tight and insulated, the air conditioning keeps it as dry as the fully conditioned space upstairs.
It's a lot of work, and you may want to stage it. In terms of thermal performance, air sealing and insulating the first floor walls is primary, followed by air-sealing the band joist/foundation sill & crawlspace wall and putting down a ground vapor barrier, followed closely by insulating the band joist/foundation sill & crawlspace wall, then finally insulating the crawlspace floor. But for insect abatement the ground vapor barrier and air-sealing is primary, since convective infiltration raises the moisture content of the wood, making it more likely to suffer ant & termite infestation. Insulating the crawlspace generally keeps the joists drier too, bringing them all inside of conditioned space.
The LAST thing you would ever want to do is to put batts between the joists and leave the crawlspace ventilated, which will often lead to mouse-nests in the batts, and mold on the bottom of the joist edges. In some instances there will be a rationale for adding insulation between the floor joists, but most of the time it's less problematic to insulate and seal the crawlspace.