the parts that fell out are your camshaft and tappets. the side cover holds the camshaft in place, and the camshaft holds the tappets in place, so them falling out isnt a sign anything is broken, just remove the side cover more carefully next time to avoid dropping stuff, which can potentially cause damage.
as long as the bearing surfaces arent dented, you should be fine. (including the cam gears teeth, and the cam lobes)
and like Affair said, if you didnt get the flywheel off, put the side cover back on to get it off.
you want something to support the PTO side (Power Take Off, where you would put a pulley, clutch, ect) of the crankshaft while you are messing with the flywheel.