So you are in college now, taking 15 credits of Introduction to Physics, Calculus 1, Chemistry, Microeconomics etc. You feel you can take one more class, maybe something fun. try something new. In that case, you are reading the right blog.
If you want to take only 1 credit: Try Physical Education (PE) classes! Usually they are only 1 credit and they take 2-4 hours a week. There are a lot of fun PE classes: Soccer, Bowling, Snowboarding, Foil Fencing and even Scuba diving! Why would you not want to take a class where you get some physical activity, make some new friends and try a new experience?
If you want to take 3-4 credits: Keep in mind that since these classes are 3-4 credits they are more challenging and require more time than the previous ones. In my freshman year I took a "History of Rock from the 1970s to today" class, which basically involved us listening to famous rock bands and artists from the era: Metallica, Iron Maiden, Bon Jovi etc. and discussing their influence and impact on music and society as a whole. Other options can be: "Ceramics" where you can actually make your own bowl out of clay, "Sculpture", " Video games and history", "Soccer: Around the World with the Beautiful Game" and many others depending on your personal interests and hobbies.
I would personally recommend you to take a class to try a new experience, because why wouldn't you? Hope this helps!