Please i need help with my dogs?

i have a beagle i got him when i was very young and i messed up with him greatly, i dint send him to obedience school, he will bite me if i try to take his food, he is not disciplined at all what so ever, he is 9 now and i want to get a german Shepperd, make him very well trained in all aspects you could think of but the problem is i don't know how my punk beagle with act around him, will my beagle influence him to disobey, will my beagle mess with the Shepard and the Shepard will kill him or hurt him, will my beagle corrupt his training, also can i still train my beagle, he barks, tugs when i walk him, bights people that try to take stuff, urinate and crap every were, steals my bed, yes so im also wondering on that, i no i messed up bad but i was little when i got him so i dint know better, and do the shock collars work. i have herd they don't hurt them but just make a tingling sensation.