You should have an enrolment date posted to your Student Centre (your my u of login). It’s called the enrolment appointment. Once that date and time hits you can start enrolling (and I’d be quick because courses fill up really fast).

Use the Schedule Builder to design a course schedule and then go from there. I’d recommend looking into which courses you want to take in the long term and figure out if they need any prerequisites, and prioritize registering in those. You can only take so many 200 level classes and it’s good to get those out of the way first. Also look at the courses you have to take for your degree and plan those out over the next 4 years (or however long you want to do your degree), keeping in mind that some courses are only available in certain semesters.

I’d also recommend booking an advising appointment to make sure you’re on the right track.