If the fill valve has a long arm with a float on the end, you might consider changing it out to either a Fluidmaster or Korky fill valve. Either of them is less than $10, and are available at either of the big blue or orange box stores. Check your hose from the valve on the wall to the toilet and if it is plastic looking thing, consider replacing it with a reinforced stainless one at the same time - another couple of bucks.
Shut the water off, flush the toilet and hold the handle down to empty th etank. Sponge out any water that is left in the tank, then take the hose off. Then unscrew the nut just above it on the tank and remove the old valve. Set the new one in place, tighten it down, reattach the hose (or replace it with the new one you bought - remember to measure how long it is so you get a similar replacement). Tighten everything up, turn the water on. You might have to adjust the fill height, but all of this is shown in the instructions that come with the valve. It's really pretty simple and you don't need anything more than a wrench, and then, only if you are going to replace the hose from the shutoff valve to install a new one. You might need some pliers or a wrench to remove the fill valve, but some have a wing nut.