The rotor dont freeze first of all. The caliper can seize up. This could be from a seized caliper but its more likely you have neglected your brake pad service. If you let the pad get to thin it will eventually wear down to the metal backing plate on the pad and grind the plate against the rotor. If its not pulling towards which ever side this is on its not sized its just metal to metal when you apply the brake. New pads and rotors (on both sides) will totally fix this. But if you continue to drive it that metal backing plate will eventually slip out and youll destroy your caliper and loose most of your braking power. Just so you know for next time when you hear your brakes start to squeal every time you brake. Its time for pads. That squeal comes from a part of the pad called the squealer bar and is designed to make the noise when the pads are near the end and is time for replacement.

Can see your rotor is ground down. Likely from zero brake pad remaining. Now whether it’s just worn out or one side is seized is another story. Check the pad wear on both sides. If similar, then probably just worn pads. But you will likely be replacing pads and rotors at minimum.

That’s metal-on-metal contact. 1 pad is completely worn out

Autozone will let you borrow their tools to get the job done, unless you have a 1/2” breaker bar, it will be difficult to get the caliper frame off, meaning you can’t replace the rotor, I would just but some caliper grease and pads and brake clean, see if you pins are stuck in the caliper, lube them. Then replace the rotor at home.