Forgive me if I'm repeating other (sound) advice, but you need to be yourself. Dressing differently or acting differently is only going to get you into trouble. It's trite, but "be yourself." It's only going to emerge later anyway. And people can generally sense when people aren't authentic. Still, if you're looking to improve the way you look, look around and if you like the way someone dresses that you'd like to emulate, ask him where he gets his clothes. But, wear what makes you feel comfortable and reflects your personality. Don't wear something you wouldn't otherwise just because you think it will impress someone else.
As far as getting yourself out there, is it really any different than your "straight life"? You'll go to a gay club or bar, or maybe make eye contact with someone at the grocery store. You walk up to them and say hello and take it from there. Of course, finding a club or bar that you like may take some time. Sometimes the same bar will have a different theme and crowd depending on the night, so do your research. Maybe you're not into bars and clubs -- there are generally different social clubs (gay hiking clubs, SCUBA diving clubs, sports teams, book clubs, on and on) all around the country. Find something you enjoy doing anyway, and if you HAPPEN to meet someone that way, fine. But you can put a lot of pressure and set yourself up for disappointment if you're going out or doing something with the expectation that you're always going to meet someone (I relearn this over and over.)
At first you're probably going to just be interested in sex, which is fine. You're entitled! If that's what you're looking for, then you're probably set (except the very important step of using protection consistently if you're into anal sex, whether giving or receiving).
If, or when, you're looking for something more stable and long-term, that's a bit more challenging. It can be tough out there. I'm sure you'll see a lot of profiles that address this: they're tired of flakes, cheats, liars, teases, gameplayers. You need to be upfront about what you want when you are ready to date. And sometimes it's not a good idea to have sex on the first, second, or even third date (my opinion). Sex can cloud things when you really need to get to know a person. Let's face it, you're not always going to find dating material at bars or clubs, so see above about possible other places to meet guys.
There aren't really any universal "rules" for any of this. You have to find what works for you, which may take trial and error.