how to start a small business

I am thinking of starting up a business… I have a job but i am wanting to start something of my own so i ask:
What kind of business should i start up?
What sites could help me in starting up a business.
What classes in college should i take in starting up my own business?
How do i start a new business without spending too much of my own money?
Where do i start?

- Thank you so much: answer all questions and get the best answer.

How much money do you personally need to have in the bank, to get a small business loan/to start your business. Also, what are some tips for ppl considering to start their own business. Thanks

I want to rent out a space to start my own business. I’m wondering how old you have to be to rent the property, and roughly how much it would cost (obviously it will depend on size, location, etc. but just an average/rough estimate would be appreciated). I live in Massachusetts, USA if that helps.