I have only one cupped tire, the front driver’s side, what do I need to do now?
Kinda seems obvious - 1. find out why the tire is cupped ( usually means bad shocks ) 2. replace tire and the best thing is all four or at least 2 new ones on the rear and move the rear ones up front.
The term “cupping” is frequently misused and while a “cupped” tire is indeed caused by a bad shocks, the term is also used to describe irregular wear - which is caused by misalignment - a much more common occurrence.
So an alignment is in order.
Plus the tire could be used until it wears out (if it isn’t already), but it would be best if it was moved out of that position. Putting it on the rear is the obvious thing to do, but the best tires are supposed to be on the rear, so the next best place is on the other side.
But if you have to replace the tire, do it at least in pairs.