Wait for someone experienced with goldfish to see this :) No matter what type they are, they will need colder water and big tanks sadly. I would find them their own tank asap. Your male betta is at risk being in a tank with them since they are very dirty fish, and one goldfish is too much for a 10g tank. Your Platy and betta male can live together though :)
Walmart has 2g cookie jars for cheap that your female would love! Just make sure of you get one, don't seal the cover, leave it slightly open. Critter keepers are cheap too, around $10ea.
Right now as I see it, you're gonna need 3 tanks for the fish you currently have, a large one for the goldfish, a 1-3g for your female and the 10g for your male betta and platys :)
You need to rehome your golfish. I'm not saying this to be cruel, but it's important that you do it soon. If those are the ones in the pictures, the slim bodied, long-tailed ones, they are comets. They can grow to more than a foot long and produce enormous amounts of waste - they also can't tolerate higher temperatures like fancies can. As a bare minimum, you want 55 gallons for the first and 20 gallons for each additional. They are pond fish and it takes a huge tank to keep them indoors. I've you've got 4, you are looking at easily 100 gallons plus.
Do you know anyone with a pond who could take them?
Bettas are Tropical and need warm water, Goldfish are colwater and need cold water.
I need to see actual pictures to see wether you have fancies (If they are ALL fancies you are looking at at least 100 gallons. Okay? If they are Commons, you're going to need a pond or at least 200 gallons! You see, Goldfish produce massive waste. They have an extremely large bioload. To add on to that, eventually, you won't be able to physically fit a Goldfish into a ten gallon. They get at LEAST 10" (1 foot and up is not uncommon).
So you are in a big mess here. Can you take care of the Goldies? If not, please rehome them. They need an expert fish keeper with the time, space, and money to care for them. I hate carnivals because of this. It is awful. Absolutely awful.
Goldfish are also major victims to stunted growth. :( A sad fact is that if the aquarium is not big enough for the goldfish, and the goldfish has no room to grow, its organs will out grow it and, well... Kill the fish.
so your saying those little tiny goldfish grow to be massive huge goldfish?!?! (like those big ones in the pet stores that are in the 50-100 gallons)
Yep. I go by at least the 5 gallons for every inch of goldfish rule to a point.. when they get about 6 inches, then it's major upgrading. So for right now, if they are about the size of a male betta they should be in 40g+. They grow big and fast.. and if kept in too small of a tank, their bodies will stop growing, but not the organs and that will spell dead fish. Even the fancy ones with big bellies get huge. A doctor out my way has a 75g tank with two of them in there.. big bellies with short bodies.. and they are at least 10 inches long, if not longer and the ones you have can easily get a foot or longer. Sad to say, but they are pretty much just feeder fish. Normally just 10 cents each at any pet store so honestly unsure just how their health is to begin with.
As for breeding.. please don't try just yet. It costs a few hundred dollars (at least), not to mention will sky rocket your electric bill which your parents may not appreciate heh.. As Pitluvs mentioned, you need many tanks, as well as bettas can have hundreds of babies easily.. where are you going to store hundred of individual jars and heat them all up while you try to find a place to sell them if/when the males and such decide they want to fight? (Most pet stores, especially chain ones won't buy them from a person off the street.)
For now, focus on taking care of the ones you have.. you need to still do research on them prior to taking on something that many experienced breeders still have trouble doing from time to time.
Yes, actually, they do. You have a couple of babies on your hands. A few weeks old, at that. They will ither get stunted with a bent spine and die, or they will get huge.
Myates- Not to burst your bubble or anything because that was good info, but that whole organ end exploding fish thing isn't true. Instead, their organs start to shut down and their spines become really bent. Poor dears. :(