Hi Mike, and welcome to the club..

This might be the comprex if I am not mistaken.. a rare supercharged
diesel..
My first thoughts are that the belt should be changed at 60K miles..
you need to check on any service history to see if it has been done,
if so you have 2-3 years left.. if not, then it must be high on the
list of things to do.
As far as the A/C goes. it may just need a re-gas.. they should also
check it for leaks, as that is a legal requirement.

As for DIY.. if you have the tools and necessary skills, it isn't too
hard a job to change the cambelt.. plus it's a good idea to change the
water pump at the same time.. just in case.

Common problems are weak tailgate struts, sticking handbrake linkages,
worn droplinks on the rear and front suspension..
That's really about it.. very reliable cars, that seem to last a very
long time, and drive like they have only a fraction of the mileage.

John