If your not a member of the SOC, i’d recommend that you join it as there is lots of information available which you will find useful and helpful.
Both crankcase wells need to have oil in them as they are not interconnected unless your engine had been modified from standard, without removing the crankcase doors there is no other way of physically checking the levels.
There are a number of views regarding gearbox oil, some use Straight 30, some use 30 grade castor others use Thioxtropic lubricant, fill via the large cap using a suitable tundish or similar.
The gearbox has a level plug, fill the gearbox until oil just runs out of the plug – the gearboxes are not particularly leak free, there are mods you can do to improve them but if you overfill it it will make matters worse, generally they will find their own level providing the shaft bushes aren’t excessively worn!
With respect to Coolant again there are a number of different schools, Fernox Alphi 11 is as good as anything, other antifreezes are also good as long as its suitable for the metallurgy (cast iron, Brass & aluminium) ideally with demin water – I personally wouldnt use straight water due to the potential for frost damage if you forget to drain down before winter.
Good Luck
