How Do You Verify A Club Which Is Legal?

Im considering a new club to make a donation to.
I verify patients all the time to make sure they are legit..
www.calmmp.ca.gov

But a club with a storefront?

Check with the city to make sure they're a registered business or nonprofit within the city limits and that they possess a business license?

Not sure on that one...I'm sure you'll get it sorted though. If you can't verify, I wouldn't donate.