I’ve never taken a 300 level course before so I’m not sure how difficult they are. What’s the normal amount?
It depends on the college and the student. If you’re a junior/senior, most or all of your classes may be 300-400 level. My major requires at least 8 classes at the 3000 level or above. I don’t think I took any my freshman year, but my sophomore year I believe I took one each semester. Some may also require prerequisites, so you need to be sure you’ve taken all those classes first. Upper-level classes also aren’t necessarily harder than lower-level classes; they’re just usually more specific and often smaller. I personally found introductory 1000-level lectures much harder than my 4000-level seminars.
It entirely depends on the specific class.
300-level doesn’t necessarily mean anything. I’ve taken 100-level courses that were more difficult than 300-level courses as well. Generally, you’ll take more 300-level courses as you advance, and most of your courses will be 300/400 level once you’re a senior. I took one second semester freshman year (math), and then took about 3 300-level courses per semester ever since. This was driven by my progression in my majors and minors, and what courses were available each semester, not by the difficulty level. I typically take 5 courses a semester. Second semester sophomore year, 4 out of my 5 classes were 300-level and the one that was 200-level (German) was one of the harder courses (certainly harder than music composition and dance history, both of which were 300-level).
I suggest that, unless you have advanced already in the subject, you consult someone in the specific department before enrolling in a 300-level class. I signed up for one that I had completed the pre-reqs for, and it was still way above my head; I dropped it right away. Meanwhile, I met with an advisor about what classes to try in her department, and she suggested 2 300-level classes to me despite the fact that I have no experience in that department. Completely depends on the department and the class. Don’t go in blind.
As others have been saying, it really depends on the class so you should do your research and ask people that might know about the classes you’re interested in. For example, I took a 200 level and 300 level class during the same semester that were directly related. They were numbered 285 and 385. Human Language Technology (285) was far more difficult than Human Language as Computation (385). In the 385 course, I somehow managed to get perfect scores on my exams whereas in 285, I was really messing up on the multiple choice exams. I fared better when the exams had open response sections. On one, I scored 9/10 whereas the class average was something like 2/10 on this section where we actually had to write a program/script, so the professor obviously wasn’t happy and had to curve that part. I was disappointed, lol. Everything in 385 just clicked better and maybe it was because the instructor was better at teaching. I enjoyed 385 so much that I even got to take 585 with the same professor.
TLDR; it really depends on the class, subject, professor, etc.
If you are a freshman, I would take 100-200 level classes. Sophomore…same and maybe some 300 but not too many. For junior and senior you will take more upper level classes.