Service Engine Soon is ODB2, "check engine" is obd1 (pre 96)
Generally these codes are to alert you to a situation that may cause higher than normal emissions.
Usually not things that will grind everything to a halt.
Autozone will scan codes for free, if you talk nice they may even reset them (corp policy is not to unless you buy parts to fix it)
The connector on F53's is usually ziptied to the steering column, up under the dash. Best to know exactly where it is before going to autozone. It looks just like the one on your car.