Hi
Depends on what your actual activity is.
In general there are:
Coolant, Brake hydraulic fluid , Clutch hydraulic fluid, steering servo fluid, (if fitted) engine oil, ATF or gearbox oil, tranny oil, diff oil front rear, fuel, windshield washer.
Serviceable filters there are:
Engine oil, fuel filter (may be multiples), fuel water sedimenter (diesel, if fitted), probably a filter screen in the IP. Depending on the IP, you may need to occasionally oil the diaphragm with a drop of leather-oil.
Air filter
(Filter not regularly serviced are on the fuel pickup in the tank and oil pickup in the sump)
There are usually also a number of spots to grease (Steering, knuckles, propshafts, probably suspension).
If you are about to basic the vehicle: Change / service them all.
If you are on a regular maintenance cycle: The service intervals, greas schedule as well as the spec for the fluids are in your service manual.
If you don't have manual: check out the resources on the top of the 70s section. If you are wrenching on the vehicle yourself you barely can do without manuals.
Good Luck Ralf