I figured I wouldn't need most of it. But I was told to take it, and hand it back in immediately when I'm back on Sunday. Unfortunately! I'd prefer to take it rather than get a bollocking for not listening you know!
Fair enough if that's what your unit have told you to take but don't be surprised if it ends up staying in your bag all weekend.
It shouldn't be a paid weekend, you won't start getting paid until you have passed selection and been attested into the TA. Having said that I know of some units that will then back date pay for it once you have been attested (though they certainly shouldn't and would land themselves in some very hot water if they get caught out). Work on the assumption that you won't be paid.
I'm interested in what's been issued by your unit. In our neck of the woods (15 Brigade), selection weekend is entirely in civvies with the addition of PT kit for the phys element. Obviously, you'll still need wash kit but I don't think they expect you to wear it either.