Can my 14 year old son lift up heavy weights thank you?

Yes, conditionally : It's reasonable to begin weight lifting around the time of puberty. Your son needs qualified instruction and supervision. He should begin with light weights and higher reps (i.e. 10 lb. Dumbbell curls, 2 sets 15 reps/set). No maxing out. Someone knowledgeable should spot him for bench and overhead presses. Allow for at least one day of rest between workouts involving the same muscle group.