Betta Fish: kinda first time betta owner here; anything i should know ? (tips, advice, care, etc etc)

title is pretty self explanatory, my parents used to buy betta’s as pranks to eachother but eventually got over it and would throw them at me but never gave me many supplies to care for them. this is my first real attempt at this on my own because i’ve been curious on trying a different animal besides reptiles/dogs/cats; this is the little guy and the tank i have going for him, ive already put in about $210 for him (decor, tank setup, the fish itself, plants, care supplies) and i’ll be going back to petsmart in a couple hours to go pick up a couple more things i forgot

yes i know petsmart is not really the most ethical place to be buying fish (or quite frankly any animal), im just not really sure where to buy a betta in town outside of the big chains and im too worried to get one shipped because of plenty of reasons

anything is appreciated!