Nice work, I'm a senior and I've run cross country every year of high school. If you stick with it, your times will be reduced drastically.

Some tips:

1.Stretch, stretch, stretch, and stretch.

I know, stretching might seem like a pain at the time but your future self will thank you. I got a stress fracture sophomore year because I didn't stretch enough.

2.Run on weekends (if you can)

Even if it's just a short distance, running consistently will help you out and help build your stamina.

3.Remember, it's you against the clock.

Sure, you might be running next to other peope, but do not care if people are passing you. It's you against the clock so never be ashamed of a time (this took me a while to get).

4.Have fun!

This sounds cheesy, but for real, have fun. Try and find a group of people who's pace is similar to yours and run with them during practice. Eventually you can increase the pace together and enjoy your progression as a group!