How do I find the centre of gravity and if it is the C of G limits?

Attain the current weight and balance sheet for airplane. In your POH find the weight and balance section that gives you the name of each station with it’s arm. Multiply the weight by each station arm to get the moment for each arm. Add up the weight column. Add up the moment column. Divide the moment by the weight to get the centre of gravity (C of G). Find the C of G envelop graph in your airplane’s POH. Mark your C of G on the envelop graph to determine if you C of G is in acceptable limits.