Sexuality is one of the most primal facets of being human. Within each context of the spectrum of human sexual activities, you can find appropriateness. I believe that individual preferences regarding sexuality should ALWAYS be honored, irrefutably. Each and every person is unique and special. It is a very human activity to explore sexuality, but most importantly, when or if you do, make sure that you are safe and to respect people’s boundaries and preferences. That is why communication between lovers / partners is important. That is what loving couples do! They communicate honestly with each other! Sex is a need, and I argue for the right of abstinence (if that is your preference), as well as the right to respect each person’s unique and individual preferences, IRREFUTABLY. You can achieve satisfaction of that need without any interaction with anyone else!
If you don’t have a partner to explore your sexuality with, for some people, a way to find pleasure, and relief from pent up sexual energy is through masturbating. For males, ejaculation (at least once in a while) is healthy for the prostate gland. For both males and females, I feel it is okay to learn (through touch and masturbation) about your physical sex organs and body so you know what you like or don’t like (your preferences).
Remember, humans are one of only few animal species who have sex for pleasure (dolphins do too). Also, (one of the) purposes of sex is procreation, so if you choose to explore your sexuality: respect yourself (and others) and make safety a priority. Procreation comes with it a lifetime of responsibility!
This seems to be a “sexual and body positive” resource regarding male masturbation: https://www.jackinworld.com/