An OEM valve isn't required. Any supply house can furnish a replacement.

@klem1 So this is just my gut feeling but how can I determine that the gas valve is the definite problem? The furnace is automatic and the pilot is ready to ignite but there isn't enough or any gas to start up. Maybe since its automatic it could be a signal that does not activate the ignition correctly , if that makes sense?

Pablo,this is an undertaking where any number of things can go wrong without a novice even noticing. Unfortunatly by the time he realizes somthing is wrong,there might be no opertunity to ask for help. I am usualy delighted to train but prefer doing it while looking over the students shoulder on some things.
Read this short story then ask how again and maybe someone else feels quilifided to help you out.
A fellow had just jumped from a plane on his first sky dive and realized he didn't know how to open his chute. Just as he was about to make piece with his angel,he saw another man traveling up from earth at a high rate of speed. As they passed the sky diver asked "hey mister, do you know anything about parachutes?" "No,do you know anything about gas furnaces". Came the reply.

It would be better if you try a little cleanup first (Which I assume you might have already done) . If that does not work you may opt for a replacement (a valve should not be necessary) or a professional help.