Congratulations on purchasing an awesome car, pics or it didn't happen! Color? Miles? MTX or ATX? It's good to see some new blood on these forums, especially in the 1g section.
These engines tick a lot (or rather, I've never got mine to shut up). It's just something you get used to. First things first, I'd do your generic new-to-me service- change the oil (20W-50 diesel oil FTW), air filter, spark plugs, coolant, etc. Then do the more in depth things like brakes and struts and see what all she needs before going ham on the upgrades and mods. Some of the easiest upgrades for the 1gen As -cars made before the mid-model revision in '90- are just swapping parts from the 1gen Bs over. Off the top of my head, those parts are the front sway bar (24.2mm tube vs 20mm solid), and the rear strut tower bar and lower tie bar. The Ford Probe is based on the same chassis and the GTs came with a bigger rear sway bar (18mm vs 16mm)
There's a host of information on this site, check out the stickies in all the various subforums.