How to prepare for a freshman soccer tryout?

I'm entering 9th grade this year and I promised my friend I'd try out with her. I tried out for modified team in both 7th and 8th grade and did not make it. I think I would have made it last year, but because of budget cuts, freshman soccer was cut this past year, and reinstated for this coming year. So, what should I be practicing? I haven't played in a year or two. I can run kinda fast, but only for a short time. I can run longer at a slower pace. I used to play my best as a defender, but I'd like to try goalie. I live near a park, so I can practice there, and the tryouts are late August. If anyone can help, thanks :)