Welcome!
Here is what I do, assuming it was running when parked.
Drain the oil. Change the filter. Fill the new filter up with oil before you spin it back on.
Drain the gas tank. Disconnect the fuel line from the fuel pump. Use a small one gallon gas can as a temporary fuel supply.
Remove the spark plugs. Put a little Marvel Mystery oil in each cylinder through the spark plug hole.
Remove all of the belts. You will replace them with new ones later.
Disconnect the positive wire from the coil. This will keep it from making any kind of spark that could be a problem around any gas leaks.
Remove the carburetor, and rebuild it with a rebuild kit from the local auto parts house.
With the carb off, turn the engine over by hand about 10 revolutions.
Install a new battery. With a remote start switch wired to the solenoid, test to see if the starter will turn over the engine. It should spin it very fast with no spark plugs in it. Let it spin for about 15 to 20 seconds maximum. You can repeat this step, just give the starter time to cool off in between runs. This process is intended to get oil flowing through the engine before the first start. After sitting for a long time, the bearings are dry.
Put in a set of new plugs properly gapped. I also put a new set of spark plug wires and distributor cap and rotor on at the same time. Be sure you wire it right. Reinstall the carb. I use a recycled axle lube bottle with a rubber hose attached to the tip to hold gasoline for priming the carb. You just run the hose to the inlet and let the fuel run out of the bottle into the carb. You only need a half pint or less. Run a short rubber hose from the fuel pump into a a one gallon fuel can that will act as your temporary gas tank.
Make sure that the coil power wire is hooked back up. Turn the ignition keep to the one position, but use the remote starter to turn the engine over. The engine is bone dry and it will need a little extra gas to start the first time. You can pour a little gas down the carb to do this or use some ether. You will need to pump the throttle a few times while it tries to start.
When it starts listen carefully for bad metallic sounds etc. Be prepared for a lot of rust to come out of the exhaust. Watch for leaks, and don’t let it run for long as the water pump is not working with no belt. This is just the first test to see if there are going to be major problems.
WARNING: do not use the gas in the tank, the gas tank or the existing gas lines. They will be lined with shellac from the old gas. The additives in new gas will dissolve the shellac, which is very stick stuff. The shellac will cost the valve stems causing the valves to stick. This leads to major engine damage. I know that your cousin Fred didn’t replace these things and it worked out, but that was back before they started using the high detergent packages in gasoline, like Techron, that can dissolve this stuff so effectively. I have destroyed two engines by failing to follow this advice. Gas tanks are cheap, engines are expensive.
