The most important thing to me is having a group of people who match my motivation and values. Go and attend the meeting in person or on zoom before you ever agree to join or make your decision.
ANYBODY can teach you how to write a contract, navigate the MLS, run comps, or lead generate. That information comes with every brokerage and doesn't make the brokerage special.
DON'T let them fool you by saying they are going to give you a mentor. Unless you find a single person willing to be your mentor and you've built that relationship you will NOT get one that's going to teach you the ropes.
Profit share is good but revenue share is better. Don't get hooked just because of profit share/revenue share at all.
A LOT of brokerages do not fully understand the investment side of real estate. If you want to specialize in that you need to go with a brokerage that knows how to handle it in depth.
ALL brokerages will say they do know how it works, but I can tell you from experience once the more complicated questions came up they didn't have an answer or their answer was totally wrong.
Other important questions
Are there people in the group doing exactly what I want to do? If not then how are they going to teach me?
Monthly fees?
Split?
Do they provide Listing signs?
Docusign/Authentisign provided?
Offices you're able to use?
E&O insurance?
Stocks?
Profit/Revenue share?
There are many more but these are important ones!