Hello and welcome to the forum :wave:
Shame on the Petsmart employee who sold you those fish! They're not swimming because there's no room to swim
The problem is that your tank is way too small to house anything other than a few snails or a single betta fish. Most will argue that the tank is even too small for a betta. To keep it healthy you would have to be doing a lot of water changes each week since it's really hard to cycle a tank that small because of the ammonia build up (without frequent water changes).
I'm guessing that the striped fish are zebra danios since they are common. They are big swimmers and need a much larger tank. Goldfish get HUGE and are notorious poopers so will foul the water pretty quickly. Please check out the fish profiles for suggested housing and requirements to keep those fish healthy here:
Freshwater Fish Profiles
The best thing that you could do for those fish is to rehome them or upgrade their tanks pretty soon so that you don't lose them all. I'm sorry that your first experience has turned out so badly but you'll find everything you need to know about keeping healthy fish here. We have a lot of great experienced members who are willing to help.
Shame on the Petsmart employee who sold you those fish! They're not swimming because there's no room to swim
The problem is that your tank is way too small to house anything other than a few snails or a single betta fish. Most will argue that the tank is even too small for a betta. To keep it healthy you would have to be doing a lot of water changes each week since it's really hard to cycle a tank that small because of the ammonia build up (without frequent water changes).
I'm guessing that the striped fish are zebra danios since they are common. They are big swimmers and need a much larger tank. Goldfish get HUGE and are notorious poopers so will foul the water pretty quickly. Please check out the fish profiles for suggested housing and requirements to keep those fish healthy here:
Freshwater Fish Profiles
The best thing that you could do for those fish is to rehome them or upgrade their tanks pretty soon so that you don't lose them all. I'm sorry that your first experience has turned out so badly but you'll find everything you need to know about keeping healthy fish here. We have a lot of great experienced members who are willing to help.