Girl help please!!!!?

Ok so I'm 16 years old and a sophomore in high school. I do well in school but am also somewhat popular. I have never had a girlfriend before and would really like to. There's a few problems... Every time I try to text a girl or something saying hey what's up she doesn't respond... And it's sorta difficult to talk to girls at school cuz my classes don't have many good looming girls. Ive talked to some girls before but mainly about school. How can I get a girl to like me/ go out with me???