ok so it should be at least 30 gallons. you will need to buy a stand, more filters, more deco, possibly more substrate...
With a goldfish you don't need a heater but you do need a bigger tank. Goldfish get huge but don't need warm water. Your water parameters say that the tank has not been cycled yet.
I would take the goldie back and work on cycling the tank but that's me. If you are attached to it, you can try a fish-in cycle. Its time to start reading up on it and be ready for the frequent water changes. That goldie will produce plenty of ammonia for a cycle but also enough to damage himself.
ok so it should be at least 30 gallons. you will need to buy a stand, more filters, more deco, possibly more substrate...
how many more fish can i put in?
hav 3 black mollies, 2 red clawed crabs, 1 african dwarf frog, and 1 bala shark