And if you have "no idea about the business world" the last thing you should consider is starting a small business with somebody else's money whilst studying.
However, before worrying about that (and assuming you are studying in the UK) you need to read this:
http://www.hmrc.gov.uk/migrantworkers/documents.htm#A3
In particular:
If you're an international student you may be allowed to work here when you're studying.
[ignore the bit about what you can do]
If you do work, you can't:
(among other things)
•run a business
•work for yourself (self-employed)