Regarding the house:
1. The bathroom requires at least one 20 Amp circuit with receptacles GFI protected. That circuit may also serve lights in the bathroom or you can serve the lights with another circuit.
2. The kitchen must have two 20 amp GFI protected circuits serving the counters and not anything else. A single GFI receptacle can be connected to provide GFI protection to the other receptacles on a circuit.
3. In other parts of the house there must be a receptacle within 6 ft of any point on a wall.

If the job is to have a permit and be inspected, you should have a conversation with the inspector before you start, else you will find yourself re-doing a lot.

I suggest doing the light and general purpose receptacles with #14 on 15 Amp breakers. You will really appreciate it when you are running those 3-way switches on fans and lights. Get a roll of 12-2 for kitchen and bath receptacles, 14-2 for the rest of the circuits, and 14-3 for the 3-way switches and the multiswitches on the overhead fans and lights.