Welcome! There is a ton of advice on here for new owners.
For the sake of brevity, here are the consensus bits of advice:
1) you need new belts (timing, balance, and accessory drive belts), and they MUST be Gates. Conti stretches, Dayton/Dayco are noisy.
2) do the airbox mod, it's easy and the instructions are very clear.
3) check the alternator to starter and ignition switch to starter wires, replace if necessary (it will be).
4) get a Stage 1 chip and do the exhaust mods.
5) chassis braces and a firewall brace help a lot, especially for a Cab.
6) do the dash light tunnels and put in the proper bulbs, replace the odometer gears while you are in there.
7) while the dash is out you may want to replace the ignition switch, be certain you get the proper unit (Sunset Porsche has it)
8) buy and carry a spare DME relay
9) if over 120k, start planning for a head gasket and variocam pads/chain
10) use the right pressure plate when you replace the clutch
11) don't cheap out on the motor mounts, the cheap ones are cheap for a reason
12) flush your brake fluid
There are more, but these are the big ones to start with.
Enjoy the ride!
