You should just go for it, with some exceptions. If you plan on sucking a stranger, you're taking a risk of std's. You can use a condom or not swallow, even though oral isn't as risky as anal. I've not even had as much as crabs and I've been blowing guys, so it's up to you.
If you plan on blowing a friend, just remember it could affect your friendship. Or you might just find the best of both worlds,the fuck buddy: more than friends, but not a relationship. It's great to have a guy you like (as a person) who just a phone call or text away from a blow job. Some guys want to give or get blown one time and never see that guy again. When I find great dick, I want to see that guy over and over. You'll learn what you like over time. It's quite common for guys who only get head eventually want to give head, and you already have seen some dicks you want. If you think these desires will fade away, they won't. You won't know if you like it until you try it, like most things in life.
The next step is practice. Suck and lick a
dildo carrot, banana, pepperoni, cucumber...you get the idea. Lick it like a popsicle, suck just the head, twist your head around on it, deep throat it. Learn to relax your throat muscles and breath through your nose. Guys love to have their balls licked and sucked, rub his cock all over face, look up into his eyes, moan and groan and make noise, worship his dick like you need it to live. Pretend it's your dick and do what you think would feel good. Massage his ass cheeks, finger him (rubbing a guys prostate will turn him on and increase his cumshot), let him fuck your face. Try different positions, ask him what positions he likes.
Music helps, some songs were made for blow jobs. I like to smoke weed sometimes, it really makes dick even more delicious!
Just be aware that you might love dick. I don't know many guys who tried giving head and hated it (if the guy you suck is a dick, or he smells, you'll hate it). If you're in a relationship with a woman this is going to change things. Just take the plunge and try it. You don't want to end up on your deathbed wishing you had done it.