Chuck her on the main stand and spin the back wheel by hand, does it spin freely?
OK next toe it into say 2nd gear and again manually turn the back wheel, can you turn the motor over this way?
if you can spin the back wheel by hand and it does not engage the motor then somewhere the clutch is not meshing and your motor and gearbox are disconnected from each other.
This can only be in the clutch area. (unless you are unlucky enough to have snapped a primary chain!)
I rebuilt my clutch and left a vital part out (wee pressure plate) and everything looked and felt OK, but there was no connection between the engine and gearbox.
It was the part that fits in behind the clutch adjuster and the pressure arm was just pushing on the end of the plates but not activating them!
(Is part number 17 on page 150 of Clymer in 650 book, proper name is bearing retainer)
I stumbled by accident over the part I had left on the bench and after a quick look through my Clymer bible I realised what I had done, and I have been rebuilding bikes for 36 years so I should know better!