As you have no service book, i’d have asked the seller who last serviced their vehicle and whether it was regularly serviced at the same place, then I’d call or drop by that dealer/mechanic and get copies of the service docs. That way you’d know the state of service.
But if you didn’t get such info, and can’t get it now, I’d assume nothing has been done so as a minimum, the diff, transmission and engine oils should be flushed and replaced (with new filters where required). Then look at fuel filter, air filter, cabin filter, plugs, leads coil pack, etc. Also, it may be time for new bushes and shocks, etc. It all depends on how the vehicle is currently performing, what you want to spend and how much you want to ‘renew’ your older car.
A good source of information on what needs to be done can be found on Holdens web site which outlines each scheduled service and what is replaced. Oddly 2008 VE is not listed but 2010 is and should not be different in any meaningful way. I’d look at that as a starting point and step through each scheduled service for an idea of what is done. See
here.