You could call him "Rozb'ry." How big a tank did you get for him? I see you have what appears to be API Stresscoat+. That's good; make sure you always add it to the water before you add Rozb'ry (or whatever you end up naming him)
There are other water conditioners that members of this forum swear by. Much depends on local availability.
Congratulations and welcome to a wonderful--and addictive--hobby! There's lots to explore on this site. What will you be feeding him? Folks on this forum recommend Omega One Betta Buffet pellets or New Life Spectrum pellets.