Hey, you are a new rider! It takes months to get your riding legs under you.

How do you get better at hills? Ride hills. Plain and simple.

And don't let what you see other people doing discourage you. You don't know their terrian or how flat it is for them. I ride in Dallas, TX USA- and it's pretty much flat here. So my average will be faster than yours. If I rode hills, it would not be.

Keep at it. Do not get discouraged. It takes time to get better.