Buy a users manual and read it..you'll find one via the web or DB owners club.
Change:
Engine oil and filters
Gearbox/ hydraulic oil and any filters
Diesel filter
Power steering oil and any filters..if it has power steering ?
Make sure you use the correct oils.
Empty water trap on fuel system if it has one.
Grease every grease nipple you can find.
Check/top up concentration of antifreeze in radiator.
Change air filter (or oil in air filter if applicable)
Check tyre pressures...if it doesn't have power steering blow front ones up a bit harder than recommended it will make it easier to steer.
Keep an eye on water and oil levels regularly until you get to know the old girl.
Enjoy.....and how about some pics of your new toy ?
Oh yes...never get off the tractor with the pto running...never allow anyone else near....and don't wear loose clothing like scarfs that can get caught in the rotating shaft.