How much freon shoud be in my amana heat pump, I think it is 2 ton

Depending on the system it will take what it needs. You really need to fill to the gage pressue's. And unless you are a qualified service technician I do not recommend attempting this as a DIY project

Amount is on service plate on side. It will show charge in ozs. Divide by 16 you will get the pounds,have serviceman to add gas if needed.