Re: Independent Teams?
What kind of area you are in has a lot to do with what resources are available to you. Not just the city but what part of the city. It will affect travel times for students/mentors, rental costs, utilities, etc.
Are you in a small town (Savana GA), a small city (Atlanta GA), big city (New York), literal middle of nowhere?
First, broaden your idea of who can be a "technical" mentor. There will need to be some "on the job training" so to speak and your priority is to find dedicated people to help structure and guide the team who also like building things. The technical stuff can be learned as they go.
Second, find locally owned businesses that employ people who do things that you do in the process of building a robot. That can be an IT installer, machine shop, auto repair shop, software dev firm, etc. Approach them individually and talk specifically about your need for space and mentors. Mention money only after they ask about it.
Third, find people in local technical schools and universities.
The only way you are getting space is to get it donated most likely. You will need to talk to property owners and ideally via someone they already do business with.
If you are given your own space you will need an insurance policy! At the very least whoever you are borrowing space from will need to check theirs before you move in.
Other than that you need internet, security, and electricity. Depending on where you are and what kind of water heater you have you may need natural gas. If you get your own office you have to get the locks changed. We just had to have the AC repaired recently as well. There's a lot so be prepared.
luck. Also, the businesses that employ your mentors are going to be more likely to help you. As others have mentioned don't underestimate an old school fundraiser. They pay for things and it shows initiative to potential sponsors.
In general having a 501(c)(3) makes things a lot easier but I suspect it is still posable to do without it.
Feel free to ask any questions and PM me if you want more detailed help.