First, welcome to the obsession and madness.
Next, change all fluids, coolant and oil. Get new plugs, wires, and dist. cap. New battery.
Since it hasn't run in 20+ yrs, try turning the engine by hand to make sure it hasn't seized up. Spray some WD40 or PB Blaster in each cylinder to lube up the cylinder to ease the cranking.
Try starting it. If it runs, then perform Cruiser's Renix tips (www.cruiser54.com).
A good engine scanning tool is Nick In Time's Renix Engine Monitor (REM) (www.nickintimedesign.com). This will help you see how the sensors are performing.
Once you have the engine running, focus on the brakes and tires.
Good luck. Keep asking questions. Everyone is here and willing to help.