I have 3 friends who bought a shop that was going out of business.
They just go there to tinker with their cars, none of them are mechanics, just regular dudes with jobs.
Split 3 ways, having a garage with 3 bays, a parking lot and lifts is actually quite affordable.
They let friends/colleagues/family use the shop, Not the general public, but anyone who knows them is welcome.
Buying land and building a shop from the ground up, will cost you a significant amount of money.
Such a significant amount of money i doubt a bank would give you the time of day for a loan without some sort of business plan to make their money back.
At that point, you're going to be going into a for-profit business to keep your head above the debt.
If you would like to get a garage, find one that's built is my advise.
Finding some friends who are into tinkering will alleviate the costs quite a bit too.