What simple diagnostics or simple remedies can be performed to either identify or correct the root cause of the problem. The idea is to try simple / easy diagnostics or remedies first in the hope that the issue will be resolved.
A shop would start with these basic tests:
When parked, engine on, turn steering wheel slowly from full left to full right, then return to center. Then, at center with engine off, wiggle the steering wheel quickly back and forth about 15 degrees while someone watches each front wheel. Do they both move a bit? You are looking for looseness.
Next raise the car a bit so you can wiggle each wheel while the steering wheel is held tight. Put your knees against the tire and try to "steer" each wheel.
Put a bar under the tire and try to pull each tire up and done. Again you are looking for looseness.