Nothing to sign up for.
Go to the park and try the food/wine at the various booths.
Keep in mind that even though Disney advertises F&W as happening now it would appear that the merch and most food is still from F&G. (Likely due to pre planning of manufacturing and vendors.)
You can get the F & W gift card which allows you to load $$ on to make it easier and faster to make purchases. And theres also the Remy scavenger hunt where you look for the Remy statuettes hidden around to add to the fun.