Im unsure if ill have any luck in my dating (personal) life or not. Help?!?

K, heres the thing: Ive talked to this girl 4 almost a half-year now (ive talked to her through one of my freinds). The thing is - i know what she looks like, but she doesnt know about me. But im unsure - i wasnt very succesefull in terms of dating and this stuff, and i feel like if ill ask her to meet me somewhere someday, shell take that as a sort of joke or a prank and will think that i am a sort of a stalker. And, i dont even know what am i supposed to think now. Like i said, ive never had serious relationships with a girl before, so i dont know what to do. Plus, if id tell anyone in high school i have a gf, theyll laugh at me and say that im laughing. And i dont think any girls (at least from those that i know) have a crush on me. What am i doing now?