I would suggest removing the plugs and squirting some motor oil into the cylinders, perhaps 1/2 oz per cylinder.
If you have a carb, squirt some WD40 down the throat.
It would be best to use fresh fuel as well.
Then, turn the motor with the starter until it builds oil pressure.
Some oil may splash out, but that's ok.
Put the plugs back in, and start it up.
That is probably the bulk of the wear you can easily prevent.
It would be better to take preventive measures at storage.
1) Change the oil. Used oil is acidic, and will slowly (and unevenly)corrode the emmersed moving parts.
2) Add a fuel stabilizer, or drain the fuel.
3) Fog the motor with a fogging oil
At least put 1/2 oz of motor oil in each cylinder, and turn motor with starter for 5 seconds.
Motors hate to sit. Exhaust systems, brakes, various bearings and batteries hate to sit too. Tires can 'flat spot'.
For maximum longevity, drive a car once per week until it reaches operating temp if possible.
1986 300E 5-Speed 240k mi.