The C.G. (center of gravity) balancer is a good thing to have. It's used to balance your bird, forward and aft. In the your instruction manual you'lle notice that it gives you a C.G. point to work with: IE) 4.25" from leading edge...

This is a tool you will use on future planes. I would suggest getting it.

The other is to help adjust your control throws, IE) making sure your ailerons/rudder/stab moves enough in each direction. You can avoid purchasing this especially for a trainer but dont get me wrong, this is also important but I would say skip it for now, just make sure you have your instructor look the plane over to make sure you have enough or that you dont have to much.

ap