It could be a fungal infection, balanitis, or really, as Sarah said, many other things. The only way to know is to let a doctor see it. I know it's frustrating and you want us to tell you, but no one can diagnose you online. This may require some testing, and at the very minimum, it requires a doctor to examine you in person.
I doubt it's an STD, if that's a concern.
Let us know what happens.
Hello and welcome to the forum. Getting checked out by your doctor is the best way to go about handling this. And at that time, you can ask them about Fordyce spots. Based on your description, that sounds like the most likely cause. It could be other things, most of which are harmless. Here's a list to look at: https://www.healthline.com/health/mens-health/white-spots-on-foreskin#fordyce-spots.