Is their really someone out there for everyone?

I lack of confidence bad.. I'm afraid to talk to girls because I tend to mumble when I speak. I'm 18yrs old ,live in Los Angeles.. Al my life I been a poser trying to be like my big brother, in my past I in middle school 8th grade there was this girl I liked a lot! We would talk over the phone , she liked me as well but because I was a chicken **** I never told her nothing. Man I just hate how I don't have the guts to talk to ppl too. I mumble, I want to join the USMC too, I just want to go Infantry see if I get shot out there