is it okay if I put another 2 bettas inside. At the pet store I bought it from (not a major brand) he had like 10 bettas inside 1 tank and they were not aggressive at all.

what should I feed my betta fish?

if I can't put the female what are some other things I can put inside? I know bettas are non social fish but I have a female in a 5 gallon tank all by itself I just think I could and should put more.