Is never masturbating or having sex a good thing? i read it's not a need. but have wet dream from time to time.?

Humans & other mammals are designed with factors that promote reproduction. In males testosterone has a significant effect on this process and promotes sperm production continuously. They will expel occasionally when not drained though other activity. The main sexual organ is the brain & if it learns to forgo the reproductive drive it will devote less resources to it.

Masturbating and having safe sex is neither a good thing nor a bad thing. The same applies to being celibate and not masturbaing. Nocturnal emissions are normal.