Welcome Steve!
The good news is that you are in the right place!!
The even better news is that most of your cars issues are easy to resolve. Sounds like the engine needs a good service and all the usual things like timing & belts checked any a good thrash to blow the cobwebs out.
Door locks should be pretty straight forward to resolve. Could even be that the interior Locking tabs needs to be adjusted upwards slightly to allow for a bit more travel downwards as the key is rotated in the barrel (Small phillips screwdriver, lift the tab up and you'll see a screw, undo raise the tab up a wee bit and then tighten up screw. If that does not work remove the tab briefly and rotate a couple of turns the metal block that the plastic tab screws onto, refit the tab.
Windscreen scratches can be polished out, I personally tend to leave this to the Pro's - I think last time I had it done it was £50 (that was a single wiper scratch)
New headlight bowls are available, but you'd need to check with a few folk on here that have that style of headlight... both my cars are the four individual bowls style.
Where are you located? There may be members nearby who can assist...
Look forward to seeing the car