Sock help

I was doing stockinette and I noticed in the row above, I dropped a stitch. I went to pick it back up and continued for 1-2 more row. Now it looks like this! What have I done and how do I fix it?

m

Welcome!
It looks like you have an elongated stitch. It may be the you missed picking up a rung of the ladder when you picked up the dropped stitch. Check the back of your work and you should see the bar left by that rung of the ladder. Drop down again to that stitch and pick up the unworked rung then ladder up the rest of the way.

Or, if you’ve not missed a rung of the ladder, keep working and later pull a bit one side and a bit on the other side of the st. That is, spread the elongation out over several sts in the same row and it won’t show because it’s gone.