I recently got back into sailing after 20+ years. Its definitely a bit of a minefield with all the different gear available now. In the end I decided I wouldn't find the perfect gear when I hadnt sailed for so long + I didnt want to spend too much incase i actually didn't like it. So i found someone selling a whole bunch of gear that was close to what I think I wanted for fairly cheap, 2k i got a 5 year old slalom board, carbon boom 3x 3 cam sails, mast, extension and uni. It was enough to we my appetite and have been upgrading and expanding what I have now that I know what I want. And that I do want to sail a lot, its worth investing in good gear.
Another good option if you have it in your area would be to hire some gear for the first couple of sessions.
Good luck, like others have said, if you were an ok sailor before the muscle memory will kick in, I was quite suprised how it all clicked into place. Now Im just kicking myself for having been away so long