Creatine, fish oil, B12, fibre, Vitamin D3, and magnesium are the supplements I would say most people should take regularly. The vast majority of us don't get enough from our diets/lifestyle.

Talk to a doctor, get a blood test, etc. especially if you want to really dial in on you though, it can vary a lot by individual.

Also important not to overdo it with some of these. For instance, vitamin D is often sold in 5000IU pills. You want like a fifth of that per day at most.

However, no supplement is nearly as important as a balanced diet ("eat real food, mostly plants, not too much") and exercise🤷‍♂️