I want to buy a cake pan, but I don't do a lot of baking (yet?) and I'm not sure what size to get. The one I was looking at is a 8x8 square. I prefer square aesthetically, but I don't have to have it. I wondered what do recipes typically call for? Is there a size that will be most universally useful so I don't end up having to try to modify a lot of recipes, which I really wouldn't know how to do anyway. Thank you.