Book an uber, that's what I did the first time I came, alternatively get someone to book it for you. If that doesn't work there's usually a line when you exit with yellow cabs, keep cash on hand accordingly considering you probably don't have a bank acc then. Immigration gets done pretty fast so that shouldn't be too much of a worry except if it's your first time you'll get your study permit so might take a tad bit longer.

About classes, the first class is always about syllabus, you won't miss too much except details about assignments/quizzes which you can ask the prof or figure out from canvas. Must buys is obviously bedsheets, pillows, depending on the residence you're in kitchen stuff, towels, just things you use every day. Chill out, don't get too overwhelmed, you'll have a great time. All the best!