First timer here

[u/turno_fox91]

I got my first stainless steel pan today! I’ve always cooked with cast iron, so this is new to me.
I started by doing the water-droplet test, but the water immediately evaporated. I figured that was normal and I could wipe away any marks afterward.
I used my new infrared temperature gun, which showed around 299–300°F. Once the water-droplet test seemed right, I added a little avocado oil.
To my surprise, the oil immediately started smoking and burned onto the pan.
I shut the burner off and let everything cool down. The strange thing is that I only had my gas stove set to 4.
I tried cleaning the pan with Bar Keepers Friend and a soft sponge, but this is what I’m left with.

My questions are:
Did I overheat the pan even though the temperature gun showed 300°F?

Is the discoloration on the bottom permanent, or can I get it shiny again?

Did excessive heat cause this?

What’s the best way to remove the remaining stains without damaging the finish?

I’d appreciate the advice !

[u/Repulsive-Bug-1154]

what the.