My hometown has a bookstore like this. It's open every day of the year and was the first business in the town to display a pride flag. The lady who runs the store is a bloody hometown hero who is forefront to organizing both the small town Pride and the Mural festival. They partner with the local animal shelter to foster adoptable cats in the store and whenever you purchase a book you get a poker chip to determine where a small portion of the sale gets donated to pick between three non-profit options.

It sells all manner of gifts from quill pens and fancy dice to LGBTQIA+ jewelry and does new and used books. Back before other businesses started showing support as being safe places it was the one. The town it is in is majority conservative and the people who work and frequent the shop are known to be grassroots fighters who show up to city councils to fight for all manner of progressive causes. Whenever I go back to my hometown I visit that store and I buy at least one glossy new book or a cool set of dice.

It has not been easy as over the years the store has been physically attacked. It's had windows smashed and employees targeted by bigots... But everytime I'm in there I see happy faces on teens and adults excitedly browsing or chatting who love the place.

It is possible to make these places but it requires a lot of support. It's not enough to just run a business, you gotta make a networked community who protects you back.

Potentially libraries could fill that spot (even though they aren't places of business that 3rd places usually are. And even though a lot of libraries still have a long way to go before they can really be called friendly/save spaces by minorities).