When I play

When I play my uke and I strum really fast I leave little scratches on the sound board, is there a way to get rid of it, or is that normal. does it affect the sound of the uke at all?

Scratching the top is normal, and it's difficult to remove the scratches. Luckily, it doesn't affect the sound at all. You could invest in a clear pickguard (they sell them at Stewmac.com) if you want to keep the uke looking nice; I don't think they will hurt the sound noticeably.

Here's two threads about pickguards.
http://www.ukuleleunderground.com/forum/showthread.php?t=6173
http://www.ukuleleunderground.com/forum/showthread.php?t=6167