I wanted to open Monginis cake shop

http://www.startingfranchise.in/2013/05/Starting-Monginis-Franchise-India-Investments.html

First od all you have take the franchise for the shop. The above link will help you. All the best.

I think you have got your answer. However, I think you should google for profitable business tips and ideas.

First of all, you should say about your niche. Unless, you are not specific about your interests nothing  can be advised.