She won't even notice me?

hey so I really like this girl about a year older than me we've hung out once . She knows I like her (I made it kind of obvious a while back) . I got her number but its like she doesn't know I exist won't reply to my texts ( I don't text too much I think I've texted her like 8 times total) what can I do to get her attention I really want a relationship with her