I realize you are a beginner and I have to add one thing.
Once a plane is trimmed, measure all the trims at the control surfaces. If you have 1/16 of an inch leftrudder trim, for example,
set it mechanically, move the trim to neutral, and so on for each control surface.
Once they are set mechanically your trims on the tx will be at neutral. One glance and you will see if your trims were moved.
If you have a comp radio....you can set the trim memory.

I hope this helps

Tom