I was riding today, and attempted to get on the sidewalk to bypass some heavy traffic. I didn't get perpendicular enough to the sidewalk, and the side of the sidewalk marked my wheels. There are lots of little marks, and when I'm braking on that part of the wheel, it whooshes.

Can this likely be repaired by sanding or something? I don't want to replace the wheels, if I don't have to

Thanks in advance.

Probably. Without knowing what kind of wheels or how bad the damage is, it's hard to say. Pics would be very helpful.

An emery board for filing fingernails works well.
Or a bit of very fine sand paper made rigid by a popsicle stick or such.
Lightly sand down any high spots, back and forth in the direction of rotation.Stop when the high spots/roughness is gone.
Don't worry about any low spots.

I used 320 grit sandpaper. It took about an hour and a half of sanding. I took it out for a test ride. Smooth as silk .

Thanks for the advice.