Taking the introductory chem 103 when school starts. Seems like there’s a lot of content, and a year-long HS class is being squeezed into a semester.
I took chemistry in HS, but that was a couple years ago, and I didn’t like the class or learn much from it.
Anything I should review before college starts?
Wisconsin CHEM 103 does not list any chemistry prerequisites at Chemistry (CHEM) < University of Wisconsin-Madison . However, college general chemistry courses commonly assume high school chemistry knowledge, so you may want to review that if you are concerned about it.
Since a score of 4 or 5 in AP Chemistry can be used for credit in this class, you can review study guides for the AP Chemistry exam. One such guide is linked below …
Khan Academy has archived some of their basic general chem content. Might be worth some binge watching between The Bear, House of the Dragon, or whatever shows you are into. 
My daughter only took honors chemistry sophomore year in HS, 103 and 104 at a different college freshman year, with a notoriously bad professor (super nice, super smart, bot a good teacher). Kicked her butt, she went to every office hour, met with TA’s, gathered practice tests, joined study groups, and got a private tutor for 104 before the class even started. Ended up with her second B in her life, a B she was very proud of. Having kids at 5 public universities, I learned from the parent pages that intro chemistry classes tend to be weed outs, you want to be at the top of the curve. They don’t have room for all of the pre-med want to be’s in higher classes.
I think one of the most useful tools in general chemistry is to be really solid on your algebra. You have to be able to manipulate equations with ease. If you can avoid getting bogged down with the math, that will help you focus on the new information you’re learning.
Any test prep resources for the math portion of the SAT or ACT would be good for brushing up on your algebra skills. Be sure to review exponents and logarithms.
And Madison is a chem powerhouse, so I’m guessing they have excellent resources for the course (USE THEM). It’s also likely to be very challenging.