I think having government permission to be here probably takes precedence over signing up for classes in-person. If you MUST do it in-person, you can probably do so during the first week of classes, (alternatively, there might be a later orientation time you can reschedule for) and in the worst-case scenario, you might not get your top picks for that semester. But I highly doubt they'll make you do that. Instead I strongly suspect you can get permission to sign up for classes on your own through the online system. Just press the right buttons, talk to the right people to get clearance, and you'll be fine. By the way, since I don't know Chinese very well, is your name feminine or masculine? I could not tell at all just by looking at the name spelling.