I also have an '86 740 GLE with about 210K on it. I do all my own repairs and maintenance on it. The Volvo 4 cyl is a very simple user friendly engine I will be glad to help with any questions you have once you get it going.
As far as starting up the car. You might want to change the oil right off the bat. I would also remove plugs and squirt some fogging oil into the cylinders and turn the engine over by hand a couple times before starting. I have always done that with cars that were stored, preferably before going into storage. Gas gets stale too so it might help to drain out the old stuff and replace it before trying to start it. One thing that may give you trouble is the brakes. Rotors tend to get rusty and pistons stick on cars that have been sitting out. If the piston boots are in good shape, you might be okay. The problem with the rotors is that they rust differently where the pad is in contact. Rust will cause noise and pedal pulsation. If it doesn't go away, you will need rotors. Just be careful with the brakes and change the brake fluid when you get it running. The car also uses a timing belt that you may want to replace soon. The belt costs less than $20 and takes about 2 hours to change. It's not something you would want to break.