If you have the key and it won't turn the lock cylinder try jiggling the steering wheel while turning the key. If the steering wheel lock is merely jammed that should loosen it enough to turn the key.
On the other hand if you don't have the key or the lock itself is jammed you may want to replace the lock cylinder.
You need to turn the wheel (about 1/4 inch) to relieve the pressure while you turn the ignition.
I would replace the lock cylinder.
The fuse block on a Chevy Celebrity is located on the bottom of the dash to the right of the steering column.
On the V6 the ignition module is under the distributor cap.
The power steering reservoir is mounted on top of the power steering pump.
The fuse block on Chevy Celebrity is on the bottom of the dash to the right of the steering column.
On a 2.8l v6 it is at the front of the engine behind the ignition coils.
All 1987 to 1990 Chevy Celebrity engines use distributorless ignition. Timing is controlled by the engine control module in conjunction with the ignition module. There is no provision for adjustment.
The steering and ignition will become locked on a 97 Chevy Cavalier if the key is not inserted into the ignition and turned. This helps to prevent theft.
Older Chevy's have a steering lock when the key isn't in the ignition.
All Chevy Celebrities have rack and pinion steering.
Which engine does your car have?