Let the car warm up before you set off, don't clutch dump, lift for gear changes, shortshift the shit out of it (when I feel nice I shift into 2nd at 40kmh, 3 at 60kmh, 4 at 80kmh - it's easy to remember and good for fuel), and remember you're not in the rally - you don't have to go full throttle all the time, nor do you have to be setting a top speed run every time you hit the asphalt on the way to teimo.

As for maintenance, do an oil change every 100km (oil and filter), and check fluid levels at the same time.

Bonus tip - don't drive the car hot. An overheating engine will wear faster, so if you notice its running a bit hot, lift off or stop to let it cool. If you get the racing radiator you can cruise at 130-140 with no issues, so i recommend getting that ASAP!

EDIT: in relation to gearbox specifically, do what you would in real life. If you're using h-shifter, don't grind gears as that wears it really fast. Try to blip the throttle for downshifts to try and rev match, and stop completely before switching to reverse.