Rust

Hi,
I've just bought a 1992 Fiesta LX. Very pretty, but has rust on the wheel arches (i guess i could expect that for a 13yr old car,) but there is also some rusting on the bonnet, where it looks like some stones have chipped off the paint and allowed the metal underneath to rust.
I was wondering, as the rusting looks quite artificial and not too deep if there was anything i could do from stopping it getting worse?
I don't really know anything about cars, and as this is my first car i want to take care of it.
Hoping someone out there can shed some light on it for me.
Also, the right hand side wing mirror is smashed, does anyone know where i can buy one from?
And...the inside door panel is coming away from the actual door. (not making my liuttle car sound too nice, but all these little minor faults give it character! :D) i can see some kind of white cli[ that im guessing should hold the panel in, but it slips in and out quite easily. past owner said bloke before him who owned it was quite large and used the side panel of the car to kind of lever himself out.
I think thats all for now,
If anyone could tell me how to get my back windscreen wiper working that would be great, havent got the manual yet :) and cant find the switch for it!!!T
hanks,
Sam