college student wants to develop good credit

[Deborah Palmer]

My son is currently a college student learning about investing and flipping houses with our family.  He currently has no debt but will if he continues with college.  He wants to develop good credit in order to buy his first flip. He currently has 2 credit cards with little balance.  Should he get more credit cards or not to improve credit?  Other suggestions for building his credit would be appreciated.    He works low paying jobs currently.  Also want to know how to best fund college.  Thanks.