There are 10 (I think) subjects available in the first year but you are only required to do eight of them. During Orientation (or whateva u call it) week, you will be given a booklet that will outline the 8 recommended subjects to do in the first year according to the particular line of major you choose. Some majors have the same subject recommendations as each other, don't worry. Eg. Accounting +Finance.
After the 1st yr, all you have to do is choose the appropriate subjects according to your major. The sum of all subjects completed will create you major/minor. If you choose the wrong subjects then it'll only waste your time...unless you wanted to do them for no reason at all.
For a double degree, you will complete all 8 complusory subjects in the 2nd yr...as you will also have to attend to the Science subz as well.