If you use the flaps as flaps you'll need to program in a little down elevator, just a few degrees at first to see how the plane reacts. All planes will "pitch up" (climb) when flaps are deployed and a little power is needed to bring the plane in or it will slow down too much and become very mushy.
If the flaps are on a rheostat it doesn't matter if you have too much or too little elevator at first because you can fine tune the flaps in the air to eliminate clime or dive when the flaps go down. If you feel you don't have enough flap after the first flights you can adjust the elevator accordingly to allow more flap deployment without pitch change.
Good luck, have fun.