Masturbation is often seen as a solo activity, but it can be enjoyed with a partner and when it is, it’s known as mutual masturbation. It can involve two people masturbating individually but watching each other, this is fantastic for an exhibitionist or voyeuristic thrill. Mutual masturbation can also involve people masturbating each other and letting their fingers do the talking…well, wanking really. Mutual masturbation is at least double the fun and can be a wonderful way to play, finding out what turns your partner on by watching how they please themselves and showing off what gets you off too!
Adorable comedy duo Garfunkel & Oates have a song the chorus of which begins with "Hand-job, bland-job, I-don't-understand-job". It's a reasonable point: giving a handjob can be a bit daunting for people who don't themselves have penises, particularly because a lot of people who do have learned over the years that they're probably better off doing it themselves!
The good news is that this is surmountable. If you are yourself possessing of a penis, spend some time figuring out what you like and don't be afraid to ask for it clearly. If you're the one trying to give the handjob, remember that everyone is different and make a point of asking your partner what they like the most.
There are two kinds of people: those who masturbate sometimes, and those who are lying about it.
While this might not be strictly true (there's an exception to every rule, after all) it's a pretty sound assumption in most cases. Pretty much everyone masturbates now and then, and so they should: it's a natural, healthy way to enjoy your own body and to figure out what you're interested in as a sexual person.