Have a question about deregulated electricity

So I’m moving into an apartment that is deregulated don’t know to much about it other then you can choose who to buy from and at what rate. Is it kinda like what happened the past month to everyone’s bills? It’s a two bedroom apartment, I’m not sure how it works a lot say 3 month plan, what happens at the end? Do they cut you off or will it continue until you cancel? Never had the choice to choose, has always been entergy. Any advice on this subject and how not to get in a bind if it’s anything like what just happened during the cold front. Thanks!