In order to form metal into different shapes, you will need a dishing stump or metal ring. A stump is an ideal material because it is softer than your metal so it won’t scratch or mar the metal surface. If you put a 60 grit flap disk on an angle grinder it can easily make the dishing bowls on a stump.
An English Wheel is also great for dishing. We have a small one that we use for planishing. It is hard to find one that will handle 14 gauge steel.