First year classes at universities are 200 students plus. You are not taught, the lecturer stands at the front and lectures you for 50 minutes then leaves. Every lab I ever took was run by a post grad student (one paper may not have been totally). As long as you complete labs no-one knows or cares whether you go to lectures. There are optional tutorial sessions for some papers and a lot of lecturers have office hours but mostly you help and get help from your fellow students. You take only those subjects that relate to your degree so it is unusual for a science student to take an English paper for example. Except for post grad you don't go on to further study. You don't to university then medicine or law university is the medicine and law (this seems to vary in the US).
College sounds more like an extension of High School. But then many of our high schools are called xyz college.
Having studied engineering, which is at a university, the freshman classes were always huge with a lecturer standing in front. Some classes are smaller, like math and as you specialize -- I was civil, so geology and soil mechanics etc. But early lectures were just a professor up there teaching the class, even my hated "heat, mass and momentum" where you really had to follow the diagrams and math. But professors were available for help. And they were professors. That was so long ago, I cannot stand by that now. I have no idea what goes on schools now.
