Any tips for SUP (Stand up paddle boarding) techniques, do's and dont's and purchase?

Rent first, wider and longer are better. Start out paddling on protected cove or bay, less wave action. Enjoy yourself.

The firmer the board, the better the ride.

Is that like the bigger the cushion, the better the pushin׳?

@zenzen No, it’s a literal statement, with full knowledge that there’s a double entendre in there. :D

I went SUP with rented inflatables. The pump they provided us was too weak to get the board up to its recommended psi, so that made for a morning of really dramatic flopping around- by both the board and me. I ended up enjoying myself while sit-down paddling for half of the day to avoid ruining the trip. Later, I tried a rigid board—much, much, MUCH better.

I’ve only done the rigid one. About three times now and getting better.