Either keep them far away with your shadow projectiles and make them play YOUR game, or use a select few moves to push them into a corner, where IMO, Noob thrives. You can use b+1,2,1,4 followed immediately by a shadow tackle to move them across the stage towards the corner. You can also use b+2,1,3 to push them as well, as the last hit is a kick that sends them pretty far. Once they get close to the corner, make sure you dash your way in there to close the ground quickly.
Take this all with a grain of salt, as I'm no expert Noob player (or MK player at that) by any means, but I'm pretty familiar with him.