Hi and welcome!! I think you will love it here!!
Here are a few tips I wish I had known before getting my first betta! I made a lot of mistakes that unfortunately my fish paid the price for.
Researching before making the decision of a living thing is always a great idea so I applaud you for that!
Water quality is crucial, so get an aquarium syphon and do water changes often! Every tank will need a water change per week or multiple changes per week for smaller tanks. I always did daily cleaning of tank bottom with an aquarium syphon to rid uneaten food and waste but every few days would probably be ok.
I recommend a tank of 5 or more gallons as ammonia builds up quicker in smaller tanks and you must work hard to keep the water parameters at safe levels. I wish someone had told me that! It is also rewarding to see the lil guy or girl swim back and forth with the extra space!
Read about the aquarium nitrogen cycle and learn what PH, Ammonia, Nitrate, and nitrite is before purchasing your betta.
Tank temp is crucial , an unstable tank temp can weaken their immune system so get an aquarium heater and keep the temp around a steady 78-79 degrees and a floating glass thermometer to keep track of it.
Proper diet will keep them thriving so get a food with protein sources as the first few ingredients instead of just fillers like wheat.
They can tear their fins on sharp decor/ plants so always get soft items and items without rough edges to decorate the tank with.
They come from heavily planted areas with lots of top cover so plant heavily.
IAL or Indian Almond Leaf is a favorite of many bettas and great for their health. It provides stress releif and anti bacterial propeties. The tannins turn the water a brown color but it is actually good for them!
You need an aquarium water conditioner for any water going into the tank. It rids the water of heavy metals and other things!
If you are not sure of something as far as tank setup, food, tank temp, water changes, ect just ask and members here will give advice!