Yes, CAM is a Scrabble word!

Letter values in Scrabble US: C 3, A 1, M 3.

Is it a valid word?

CAM is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

a river in east central England that flows past Cambridge to join the Ouse River
a rotating disk shaped to convert circular into linear motion

Also: river cam, cam river.