Is a 10 gallon tank too big for one? That's what I was thinking I might use. Do females need other fish with them? I was thinking male. I was thinking a beta because they are beautiful and you only need one. I don't have a budget in mind-this is still all theoretical. Parents said that they are open to the possibility of a beta fish or a hermit crab if I'm the one paying for EVERYTHING, including continued foot and maintenance, which I haven't done before. I'd be doing all the care, obviously. My current budget is that I don't want to spend ridiculous amounts of money while putting together a good habitat for betta or hermit crab-because there's no set timeframe on this, the I can probably save up a good deal of money.
A big tank is never too big for a fish!
Well... unless it is pools sized.
Bettas don't really need other fish but it is nice to get them a companion. Be careful because there is a small number of bettas that will kill the other fish. Never put two bettas together unless you plan to breed them but after breeding, they should be separated. Also, it is tricky business to breed them so best do some research.
You should always clean new items including sand before adding to the tank and aim for fish hidey homes that are not to bumpy because they can be a pain to clean. Avoid the ones that are big and have a small number of exits because the fish might get stuck. Out of all decor, you absolutely need a hidey home or else your fish might get stressed from being exposed all the time.
You need to get a filter because they can survive off of no filter but they will not be a happy fish. Also do not forget a water heater. Bettas are tropical fish that live in rice patties in the wild, where they live can be pretty warm. Preferred temp. is 74-79 F get a thermometer if you can. The best filters are the three in one; bacterial, chemical, and grime filters. But if you can't find one then buy a normal grime filter and put bacteria balls in it.
Most important thing!
You need to get the tank before putting the fish in it and treat it with a water conditioner if it is not from a well or water bottle water. When you add the fish, float the bag on the tank, safely, for 10 minutes or so. This allows the fish to acclimate to the tank temp.
If you are to get the betta a buddy please do a quick bit of research about their preferenced temp., social needs, and tank size. Like the common goldfish, it actually needs a 20-gallon tank (people put them in 2-gallon fishbowls most of the time with another goldfish, in all they need 32 gallons of water or so when you add another goldfish. Elmo misleads.

) and a fancy goldfish needs a 10-gallon tank.
Do not fret to much about price because you can slowly add up more items. You can get the simple necessities like sand, hidey home, filter, water heater, and a water conditioner.
For food buy floating pellets or sinking pellets never flakes.
For treats, you can buy frozen or live bloodworms.
Well... sorry for the unorganized info... I hope that this helps though!
