How to easily run a mile?

I'm in cheerleading, and we have to run 1.3 miles every day after school. I've never really ran before, and it's kind of hard to run the whole thing without stopping. I can do it, but I was wondering if there's anything I can do to make it easier? I can't stop and walk and I can't get a drink until I finish the whole thing, so staying hydrated won't really help. Thank yaaa.<3