@woahitsgab The student doesn't get a notice an hour before like for work. But the student should go autonomously when it's time for class - unless you have them queued to do other things and it just adds to the queue - or unless your sims don't have full autonomy.
You will have to go to the work button on the active sim (the briefcase icon) and the class schedule should be there. This is the place where the 'go to class' button will appear - but the button and the prompt in their queue does not happen until the minute class starts.
All of this is for off-campus students (which is what mine were). If your student is in on-campus housing (dorms) they should be able to go to where the class will be held early and hang out for a bit to wait for class.
If you aren't getting the 'go to class' button in the 'work' area (by your sim's needs, etc.), can I please ask if you have Mods or CC? If so it may be possible that they are interfering and we can troubleshoot to eliminate that possibility.
Following are some good gameplay tutorials for Discover University that may be helpful"