HELP..I can attract guys attention but I don't know where to go from there?

I'm 16. Look, many girls my age have had sex. I have no intentions of doing that, simply getting to know guys, hanging out, maybe kissing, enjoying ourselves. It's summer, you know? I've never had a boyfriend but I have kissed a few guys my age, that's all. I see other girls being able to pull guys wherever they go, even in the daytime when they're just shopping. I don't know how to do it? I get told I'm good looking but I either freeze and can't say hi back, or I'll keep walking and won't look at them. How do I progress in situations when guys talk to me? Also, when teenage boys say "Hi girls" as you're walking down the street, are they taking the piss or genuinely interested in speaking to you?