Just ask a experienced modeler to have a look on some strategics points like CG, controls surfaces moving correct way, radio control and engines properly fix.
Let the experimented modeler make the test flight and enjoy your flight lessons. I am sure the work you involved in the building of your lt40 will give you many hours of fun in return.
Kadett lt40 design forgive many errors in building and flying.

my only advise is DON'T START ALONE OR YOU WILL LOOSE YOUR PLANE

good luck and welcome in the hobby !!!