As cr250 said, there is the transmission "free-wheel" knob that you have to lift to get the tranny to roll.
As for bringing it back to life and the parking brake--
Change oil & filter and tranny fluid--takes regular 10W30 motor oil for both, or upgrade to synthetic.
Fill tires to recommended pressure.
Replace spark plug, air filter and battery. Clean up battery cables/connectors.
Empty any old gas in tank, if any. Replace gas line and fuel filter.
Give carb a good spray down with carb cleaner, inside & out.
Stuck parking brake--you'll have to get underneath the tractor with some PB Blaster or WD40 and try to
free it. I imagine it's rusted after sitting so long.
Fill with fresh gas & give it a try...
Rattosh51
YT6800