Welcome to the Betta World. I consider myself to still be a newbie, I got started about 8 months ago and have been addicted ever since. The stores will tell you that they're fine in room temp water & in small containers, I think just about everyone of us started out with that belief. However, they THRIVE with bigger living space & warmth. I started out with a 1g filtered aquarium & lost my 1st beautiful male within 2 weeks, DO NOT follow the instructions that came with the aquarium. After he passed I did a lot of online reading & found out how wrong I was & have been working to improve their habitats ever since. I now have 2 10g tanks & 1 46 g tank, we are all much happier. Your tank is going to be cycling for the next few weeks, this is what a new tank does. Definitely do frequent 100% water changes, I was doing 50% every couple of days on my 46g tank while it was cycling so for your smaller tank its even more important if you want to keep your Betta alive. Most instructions the aquariums come with say let run 24 hrs, then put the fish in & then do a 25% water change weekly, IME this does not work with a tank that small, you need bigger water changes. If you check online at Wal-mart, Petsmart, Petco you can usually find some good deals on aquarium kits which typically include the hood w/ light, filter & heater, I've had the best luck at Petsmart. If you can get at least a 5g your Betta will be ecstatic & much more active. Best of luck with him.