You click and hold on the tool that looks like a T and there you should see "Type on a path tool" click on that and click on your path you created previously and type.
Answer:
Ground is the background surface used to paint on. It helps to prime the surface by making sure that the paint will adhere the materials onto the surface better, as well as helping to protect and provide extra durability to the paint. There can be oil, acrylic or latex primers / ground.
