Connie...An easy way is to make the cake then ice and purchase decorations in the section of the store/grocery store that are edible and place on the cake. The items are nice, full of sugar, but it's an easy way to make a pretty cake. Good luck!
The first step would be to pick your theme. Then you can google that to get ideas. Then are there certain flavors they really enjoy? Here are cute pumpkin cupcakes frosted like roses for inspiration but there are really endless choices until you begin to narrow down the theme and flavors https://familyfocusblog.com/pumpkin-cheesecake-cupcakes/