I’m in Psych 100 at Penn State as a freshman and it’s been easy so far. FWIW, I also took IB Psychology in high school and got a 6 on the exam, but was unable to get credit because it was an SL class. Most of it is just memorization. One difference between high school and college, though, is that while the tests are multiple choice, they’re based on application of concepts rather than knowledge of the concepts of themselves. I could see how that would be tricky for some people, but it’s not too bad.
Obviously it depends on the school and the professor, but for me, Intro Psych was the perfect freshman gen ed: An interesting class that’s easy to do well in. So I would say it’s a wise choice to take it :).