Porpauly:
First and foremost, "Welcome" to Pelican and Porsche 944 ownership!
Second, George and Chris above have given very good advise with regard to our 944 cars.
I like George above, have owned and driven my 1987 944n/a since day one with no really big problems. Yes, problems do arise from time-to-time but all in all, this car has never left me stranded, ever. It has never, ever, leaked a drop of oil and is now reached over 163K miles with it starting-up right away after being put away for the Winter months in a cold garage.
Okay, enough bragging now to the real info:
One thing to look into, if you plan to keep your car for a long time, is books such as:
The Factory manuals for the 944, as a set they are your best reference for this car, as well as the Haynes manual. While the Haynes manual is not considered the "best" reference for our cars, it does contain a lot of pertinent pictures associated with the important (factory dictated) maintenance. These two (2) sources have been in my possession for years and have paid for themselves many times over!
Another important piece of information comes from the cars maintenance records. Hopefully, the PO (previous owner) sent them along with your car when it was purchased, and by reviewing these records it will give you a very good picture of how the car was kept in its previous life, or rather lives depending on how many owners there were in the past. By reviewing this information, you will know precisely what needs to be done next to your car.
If there are no records with your car, then, like others have said above start with the basics and begin to change out parts for newer ones, so as to keep your engine and car in tip-top shape.
Hope this helps, and good luck with your "new" car! Don't forget to post pictures of your car soon...some here get a little testy if you don't do that. LOL