What to do if i have a blackhead on the side of my penis?

Here are some ...: Without a direct look, an accurate Dx is hard to come by. But, clinically, it would most likely represent a long-existing overgrowing hair-follicel-related sebaceous gland, which is harmless and requires no Rx except superimposed infection may occasionally kick in. So, wait and see if being comfortable; but, see Doc timely if in doubt.