Keyhole and cylinder is completer knackered

Was greeted by this lovely sight after getting groceries today... not sure how to go about "repairing" this. My only experience working on cars is changing my oil and brake pads, so please forgive these dumb questions.

The car is really showing its age, so my only real goal here is to have a method of getting into the car if the keyfob battery or car battery dies on me, preferably without bashing in a window.
1. Is it as simple as buying a new cylinder set like this and carrying around that extra key just in case? Or some similar product? idk how to tell what exactly I need to replace, and with which part
2. If that were to work, I assume it would be impossible/prohibitively expensive to have the locks "cut" (or whatever that end's equivalent is) to match to the same key?
3. Any other creative ways to let myself in? like maybe getting some kind of slim jim or the like, and tape it to the underside of my spoiler. not afraid of jank, so if you have any ideas lmk

TIA

 

That would really bug me if I saw that every day. What is your insurance deductable? That is vandalism and you could get it fully fixed properly for the cost of your deductable or less.