I would stay clear of an SBA loan. The rates are very high, you would be better off self funding. I would suggest trying it out of your home before incurring the overhead of a bakery. I knew someone who baked custom cakes out of their home for birthday parties and other special events. I would start by doing something like that. Then once you have a loyal following and some revenues to show for it, you will be in a stronger position to get a bank loan (at reasonable rates). Good luck...
I recommend that you review this flowchart for small business loans - it gives information about what you need at each step.
If you can startup with your own money, it is the best way to go. However, if you need to ask for a loan, then you need to write an excellent and thorough business plan to present to a bank. Since you will be a new business, you will need to include a lot of research in yoru business plan. A business plan of 10 pages will NOT cut it. Expect it to be 30 pages + if it is done right. Since it will take you a while to write it, I highly suggest going to a library and checking out some of the books they have there on business plans. Experience is not necessary, but a plus, however if you do your homework right, it will pay off.