One of the few things I wanna mention..
Don't start training benchpress, dumbbell presses and shit for the chest.
No chest training except those push ups IMO.
Focus training on the shoulders. Standing DB presses, will give you good training of the stabilizing muscles as well.
Back training is important, try DB rows or one handed seated pulley rows.
Make an effort to learn how to do cleans. Then start incorporating them as part of your leg and back routine. clean&jerks will work most of the body, give you strong legs, yet you'll stay explosive, imperative when being a boxer.
If there's any lifter/coach who knows Olympic Lifting in your gym, I recommend asking him for suggestions on how to approach learning the snatch and the CJ. Without this expertise, I think you should stick to only trying the CJ.
In a nutshell: Leg strength, shoulder strength and ab and back strength. Those are the areas to train when being a boxer IMO.
YIP
Zack