Your tank is way overstocked and contains fish that can't live together.
For example the "black moore" and goldfish are both types of goldfish, I assume the feeder fish are either goldfish or guppys? The oscar will grow huge, if it's small it's only a baby, they grow over a foot long and need a 75 gallon tank to themselves, the sucker fish is probably a pleco or algae eater? They will both grow huge. These are all tropical fish while your goldfish are coldwater fish, they are not compatible, you need a heater for the tropicals and can't have a heater for the goldfishes, they will be too warm.
If they are swimming backwards it's probably due to a number of problems... which ones are swimming backwards? The goldfish are probably too warm because you say the tank is heated. Also it's already overstocked so they are probably getting ammonia poisoning.
Did you cycle your tank? (No that doesn't mean letting it sit and run for 1 day or week or month or year, you have to DO something to it to make it cycle, you add ammonia in the form of household ammonia or a fish... in order to grow bacteria which will eat ammonia and process it through the nitrogen cycle down to nitrates.
Problem is even if you did cycle your tank your fish are still going to suffer because it's ridiculously overstocked. You could have MAYBE one goldfish in there. Just one. You are still really pushing it if you put 1 goldfish in 10 gallons. They are huge and messy and make a lot of waste.
I would take all the fish back to the store and complain t hat they didn't give you any advice about how you could keep these fish and come back and put one betta in your 10 gallon, it would be a good home for him and easy to care for.
