you should start off with basic yoga first before jumping into hot yoga
one of the studios I go to 90% of people on this forum would not survive the entire 90 minutes.
some yoga studies have low end hot yoga, and some have crazy hot yoga where it is super hot inside and very tough. for me I take 2 big things of water mixed with electrolytes and make sure i am super hydrated before the class starts. you sweat out so much that is what you have to do