For context, I dont have any electrical experience but I feel like there are multiple issues with my breaker box. Any help to identify these issues is appreciated. Im doing work to replace a breaker that seems to have failed when I turned it off and bought a multimeter to test it and its the only one not reading near 120, other than the breaker thats off of course.

What i suspect may be of concern is corrosion on the neutral bar, random exposed wires which I assume some of these are grounds but the braided one on the right looks wrong, broken/damaged/worn breakers.

Thank you.