Oh, it’s all about the costumes , isn’t it?

But when you are learning, sweating, and focused on the movements, you should be comfortable!

Ideally, you want to wear something with some stretch, breathability, and something in which you won’t worry about sweating !
You can think yoga clothes, T-shirt, crop top, whatever you are happy with, and comfy pants!
Footwear:
Totally personal.  Classic indian dance is done barefoot.  Bhangra is done barefoot.  Belly dance is done both barefoot or with slippers or low heeled shoes in class.
I choose to wear gymnastic slippers like these – while they do not really work with orthotics, they protect me feet from any possible debris on the floor and allow my turns to happen more easily.
If you need to wear orthotics or just feel better with more foot support, then you can dance in whatever shoes work for you!