I will qualify my answer by saying I am a beginner also, however, I have spend quite a bit of time researching CG on my Great Planes PT 40 trainer. You didn't mention what kind of plane you had for your CG issue. I would suggest you spend some time learning about CG - it could save your plane. Most, if not all, trainers are designed to balance on the main wing spar. If your wing spar is 4" from the LE, then you should be all set. I built a simple little balancing jig - piece of plywood with two dowels topped with pencil erasers. Place it at the 4" mark and let it balance level. (Slight nose heavy is preferred as others have mentioned).

Also, check your build plans and instructions. My PT40 plans had the CG at about 4" and that was incorrect. First flight by my instructor/test pilot was scarry to say the least, but managed to bring it down in one piece. Change the CG to balance on the spar - which was 3 1/2" and what a difference. Flys great now.