This is especially noticeable while doing loops. Trimming the plane out is the next step. Fly around for a few minutes and get the feel for the plane. You want to do the trimming on a good day with reasonable lift. Its much to difficult to trim new planes in bad air.
First task is to get the balance right.
If you are flying with up trim you are probably nose heavy. Get some altitude and put it in a dive. If it pulls out of the dive land and remove some nose weight. What you want is a very gentile pull out or no pull out at all. The further back you can get the CG the better.