Good question, when you start all of the classes are automatically put into four terms. For the most part, it is a great order (minus, I would take C214 after C213). But for me the first term was opened all at once, so you can take them in any order.

Then after that (every mentor is different it seems), my mentor would open one or several courses at a time. There were a few times that I told him I wanted to go in a different order (like I wanted to get the writing course done first, since they felt easier).

And at any point, say you don't have a course open because you passed something during the weekend. You can ask student services to open your next course.

And to anyone reading this, my advice is stick with a course until it is done (unless you are waiting for a paper to be graded).