There isnt any bad effects from masterbating unless of course, You dont use lube and do it too hard, can blister you, but that'll go in a few days, Or using Skin irritating stuff like shampoo, Other than those, there isnt anything im aware of.
It is not bad only some people that seem to have religious affiliation seem to have any real objection to it and when you ask them why it is bad the information they give you turns out to be...
If you're asking if it's ok to twist your hand on your penis during masturbation, absolutely. I'm assuming that you are young...you're lucky. It took me 30 years to discover that!