I'm not a baker per sa but I looked up some info for you. Hope it helps and welcome to DiscussCooking. There are a lot of great bakers here at DiscussCooking so hopefully someone will give you some tried and true ways.
For a Moist Cake
The main reason cakes become dry is they are over-baked. As a rule, check the cake at the shorter end of the baking time range. If your cake doesn't test done with a toothpick, return it to the oven for the full baking time.
No one wants a dry cake. To ensure a tender, moist cake, gently and briefly fold the liquid and dry ingredients into cake batter. The lighter your touch, the better. A light touch prevents the protein in the flour from forming into firm strands of gluten.
Moist Cake:To make any homemade or boxed chocolate cake recipe moist and fluffier, add a spoonful of vinegar to the dry ingredients. you'll be amazed at the difference