People who work at the pet store often will say whatever you want to hear so you will buy their fish. Most bowls , even with plants growing inside it, will not provide enough surface area for oxygen exchange. Without enough oxygen in the water the goldfish will go to the surface and gulp for air, which is something you will see often with a goldfish in a bowl.

How big is the bowl? I recommend you start out with a 20 gallon aquarium, which will allow room for the goldfish to grow.