How to properly calculate acoustic panels? new reheresal studio in home???????

I'm brand new and an expert in all things construction .
Not acoustical treatments. I have just built a sound proof music studio that is 12-6"x 18' x 7-4" ceiling height in my basement.
Now the question is how to properly treat the room with acoustical panels? how many and where. I have a band that will play in there. I am a drummer and so is my son, so sometimes its a drum studio but it will also serve as our rehearsal studio. I am planning on acoustical ( drop ceilings) floors carpet or carpet? walls drywall.
need help! spent a ton and don't want to blow it now!
any advice is appreciated.