I learned it the hard way at college. The prof just blasting off in a flurry of greek and us trying to keep up. Eventually he resorted to using the gothic alpha

I learned it the hard way at college. The prof just blasting off in a flurry of greek and us trying to keep up. Eventually he resorted to using the gothic alphabet and at that point I gave up. Every single field of math appears to have their own conventions and even these are but guidelines smart people often bend for perceived benefit. So I can’t really recommend anything other than learning the notation with the field. If you find yourself at loss, chances are you have missed some of the context and should backtrack.