How to I get ready for Soccer season this fall?

Okay, so when I was little, I played soccer ALL THE TIME. but I haven't played it in 3 years, and this year, I'm required to take a sport, so I chose soccer. And I still have really good aim and drilling skills, but my problem is endurance. I am not the best runner, and I tire easily. I want to be able to, in the two months I have before the season starts at the end of August, before school starts, be able to run the amount a offense player can run. I mean, I can play any of the choices, but a soccer player generally needs the same endurance, so places can be switched. I have a treadmill and a wii fit available for me to use, and a big yard/street I can run around :)