Question

who can start startup-business?

Answer 1

Anyone can start. this is a good thing about startup-business. If you have a great idea, you can start a startup. 

Just you have to think about your why? Why do you want to start a business/startup. 

And how to start? I just explain in this question (https://brainy.pk/qa/41/how-to-start)

Answer 2

Everything you need to know about how to start a business. There are no limits on who can become a great entrepreneur. You don't necessarily need a college degree, a bunch of money in the bank, or even business experience to start something that could become the next major success.