Swimsuit under clothes for arrival. Don't forget to pack your underwear in the bag.
Personally, I don't think I could walk out in a dry robe / onesie or other fluffy garment so. Clothing wise, you're after flexible fabrics and looser clothing to avoid fighting with stickiness.
In the summer, a flowy dress goes well.
Winter, a jumper and loose trousers - not skinny jeans...or after one particularly ambitious evening...gym leggings.
I swim in the evenings so not so fussed about leaving sans-bra if I'm going straight home. More often in Winter as jumpers, coats make it hard to notice. Summer, I will fight one on. I've learnt to do it up from the back though, which means you don't have to swivel it. If practical for you, perhaps try a bralette or bandeau
Feet wise, I see some people in flip flops or sliders, and some by the wall on the side of the pool - so these could be worn up to the pool edge. Check with your pool though....Plus worn in the shower and changing rooms before changing to regular footwear.
Similarly, bring 2 towels - one to dry with and one for the floor?
Cubicable-wise, I'm more bothered about cleanliness - but scope them out a bit, rather than darting in one as soon as you walk in. There's probably an area that feels a bit nicer than the rest....For me that's one with the drain at the door rather than under the bench and away from the club swimmers, banging and clattering.