In order to be a cook, you have to love food. You have to be open to taste all things...even an octopus with peanut butter on it. Or a pickle with peanuts. You have to have a stable stomach like me....
Basically, a pastry chef cooks pastries. I don't want to be so blunt here. Pastries are food items that are prepared through baking. Cakes, pies and similar dishes would be examples.
Chocolate chip cookies.... little easy desserts...veggies....potatoes. You could also have a go at a traditional dish like shepher'd pie or spag bol if you have a good recipe.