Okay, so here's the thing: I think I only like girls. I don't really feel anything with any guy I've ever been with. I'm also kinda scared to come out as lesbian. Advice?
There's no rush to come out to anyone, just do it when you're ready. I was scared to come out too but when I did everyone was very supportive and it went well. Unless you're somewhere where it wouldn't be safe to come out at all, you should just do it when you feel ready.
If you don't feel comfortable coming out yet, you can always take the time to become more confident in your identity. There are plenty of online resources out there like this one. Buzzfeed has an LGBT section that's pretty good. There are also a lot of cool Youtubers out there who make some funny and entertaining videos. Be careful though because some of the websites will stereotype LGBT people so just remember that you don't have to follow the stereotypes. You don't have to change the way you dress, unless you want to, of course. If there is an LGBTQ club at your school or in your community I would recommend joining that.