Well, some majorly important things are to make sure you manage time well and are organized. A strong team structure is really helpful too. But depending on how many students your team has or will have this year, it might not be really important right now.
Also make sure that you know what you're doing before build season starts. Programmers should learn how the code (which ever you plan on using) works, build kids should know how to properly and safely use tools and where everything is in the robot room, etc.
If you guys need help with anything, you can PM me and I'd be glad to help you. You can check out our website too. It has a lot of resources and things like that.
mercury1089.com
Good luck with you're first FIRST!