There are many, many posts on this - some with detailed lists.It's worth finding those. Here's just a rambling bit of info.
In general most all the mounting hardware should be thrown in the trash. Replace with good material Grade 5 equivalent is actually fine and shouldn't be brittle.
Use a good fuel filter and different HD fuel valve. The gas cap will leak, solved with a new washer and not over filling. There will be intake leaks at the carb and or manifold and or engine interface. The engine should be broken in oil rich. The plug (NGK B5HS) and plug wire should be replaced.
Plan on adjusting the carb with the needle e-clip and getting some replacement jets as the engine breaks in. Watch the spark plug for air/fuel condition.
Adjust your clutch cable sheath length (down) as necessary, lube the correct points and adjust the clutch.
Get a dual pull brake lever on the right side.
Be prepared to replace the head studs and head gasket.
Solder and shrink sleeve the wiring connections. Don't use the little (red/black) push button kill switch. (The yellow orange throttle grip push seems to work fine, IMHO)
If you decide to use the stock chain and bolt on sprocket, don't ruin your spokes, make sure the chain gets adjusted as it stretches, get a good tensioner that doesn't bail into your spokes, etc….
Get an expansion chamber and silencer. And at the very least open up the intake and exhaust port and replace the intake and manifold gaskets.
Point being there are detailed posts on all this stuff