Hello,
Good way to find out about the relationship between 4-H and FIRST would be to go here:
http://www.explodingbacon.com/4-h-and-first/
We run independently of the schools that our students go to (think club sports team vs a high school sports team) so all of our students are either brought by their parents, carpool in, or drive themselves to wherever we happen to be meeting.
The one big problem we've run into is a lack of a home, we've built in 5 different spaces and store all of our stuff in a storage unit or garage during the off season. 4-H provides our team with meeting space during the off season but unfortunately they cannot give us a build or storage space.
We're working to solve this problem.
I hope this helped, feel free to post or message if you have any questions.