First, get the engine turning, remove spark plug, squirt a little oil into cylinder to make rings slide easy. When in doubt, remove drive sprocket cover, and be sure chain is squarely seated on drive sprocket, if cocked to one side, chain may snag on casting, preventing wheel movement.
As to the clutch, let it out very slowly, until it breaks in, rapid release will lock rear wheel, feather clutch out while slowly pedaling