Hi Andrea!
I drink about 100oz of water a day. That’s on the recommendation from one of my teachers to drink half my body weight in oz every day. Before doing yoga, I definitely did not drink enough water. When I can I try to drink Smart Water. I try to replenish electrolytes after class by drinking a smoothie with coconut and/or banana in it. Today I got some Emergen-C, and am actually drinking it now. Hopefully it’ll help me tonight in class. As for sweating, yeah I’d say I sweat pretty excessively during class.
Hope this helps!