If you're literally unable to feel much, or any sensation (good or bad) in your genitals, then that would be something to talk with a healthcare provider about. But, if it's more that whenever you try to masturbate, touching them doesn't generate any pleasure, then that might be something we can help you dig into a bit more.
As for kissing, you may be right that some of i has to do with inexperience, or even with kissing people whose kissing style doesn't do it for you. It could also be that kissing just isn't something you enjoy. Kissing gets presented as something that everyone enjoys. But as with any kind of physical touch, the reality is that some people love it, some people don't, and some don't have strong feelings one way or the other. Does that make sense?