Since you don't post an e-mail address, I'm shooting this to you here, but I hope other would-be bakers are listening, too.
Get yourself a copy of The Cake Bible by Rose Levy Beranbaum. It's available in paperback, which couldn't run you more than $30 or so. Most of the questions you've been asking here over the last month or two could be answered much more fully in the comfort of your own home by this one book. If you're really serious about starting a baking business, then you need to know in your bones the fundamentals of cake baking, and not rely haphazardly on the know-how and kindness of strangers. This is the best, most helpful advice anyone can give you at this point.
My intention here isn't to chase you away from the boards, but to help you find the knowledge you need. Starting a food business is an uphill battle, even if you've got an impeccable product. So give yourself a leg up from the get-go. You can't afford to make mistakes when the public is counting on you....
I'll say it again: get yourself a copy of The Cake Bible by Rose Levy Beranbaum.
Then read it cover-to-cover. Read it cover-to-cover again. Start baking from it -- follow her directions meticulously. Make the same cake 4 or 5 times in a row, and make sure you can make it the same every time. Then try another cake. Then another. Get to know the fundamentals, so when something goes wrong you have a pretty good idea why. When you really know what goes on in that bowl, in that oven, in that cake pan, you can maybe start to improvise.
To respond to a previous query that went unanswered: Ms. Beranbaum provides recipes for both yellow and white layer cake that are perfectly delicious and moist and not at all like cornbread.