The courses required for majors and minors vary from one program/department to another but you can find all of that information in the undergraduate course calendar:
You can't do any coops or internships until after you complete SOC SCI 2EL0 in second year, so don't worry about that for now.
Explore the course reviews section of this website, the course descriptions on the social sciences and humanities pages of McMaster's website and figure out what sounds interesting to you.
Use
www.timetablegenerato r.com to put together a schedule with the classes you like and pray that they fit together.
Good luck!