It depends on a lot of things, such as class subject, teaching style, your history and what stage in your life you're at ... Some psychology classes can shed light on things you are not aware of, but not all (for example my freshman year history of psychology class did not shed light on anything personal for me and I doubt that it did for anyone). Some can be intense - for example if you study psychological pathology. Many of psychology students I talked to kept self-diagnosing for even normal range issues after that course. But your experience will be yours and yours alone, so my suggestion is to become aware of what your triggers are, what kinds of classes you may not be ready for, what issues you feel you aren't prepared to talk about openly and study just yet.
If you do decide to take psych classes and something feels bad, do remember that your professors will probably be psychologists and you should be able to tell them about your issue during office hours. They likely will not provide therapy, but they can potentially say something helpful to you, make a suggestion on how to cope, refer you to a professional, or something else.