One other tip, in skateboarding there are two 'stances': goofy - right foot forward, and regular - left foot forward. Take note what stance your subject is as you want to make sure his face and not his ass is the focus of the photo!
Like anything, it is all about composition and light. You can shoot any subject and make it look good if you pay attention to these basic things.
If you want to freeze action with that lens, I would use '1000 or faster, though IME '500 does just fine for skateboarding pix with a 50mm. Choose a film that will allow these shutter speeds in the light that you have the day of the shoot. You can do it with a medium speed film in strong light, but I would also have some fast film on hand.
With panning, you just have to experiment a few times to find which shutter speeds work best for you. I'd start with '60 and try various speeds on either side of it to see what you get.
"Truth and love are my law and worship. Form and conscience are my manifestation and guide. Nature and peace are my shelter and companions. Order is my attitude. Beauty and perfection are my attack."
I was a skateboarder as a kid in the 60's, before the advent of modern wheels. Frequent wipeouts were a certainty, and most of today's tricks were impossible.
I get a real kick out of seeing kids in other parts of the world looking the same, using the same terms and doing the same things as the kids around here.