Driving in foreign countries - especially on the other side - is definitely not for everyone. We've done thousands of km on the other side (mostly in North America) and seem to have survived it okay, but the reality is that most other places have faster and more congested traffic than here in Australia.
I don't think you need a driving school - all you need is some time behind the wheel. Here are a couple of tips to assist:
- Do not pick up the car in a place or at a time that is going to make it a nightmare for you
- Pick a quieter time, and somewhere relatively simple, such as in the suburbs somewhere (but sometimes airport perimeters are not too bad)
- Invest in (or take) a GPS ... and make sure the non-driver is very good at using it
- Speaking of the non-driver, they have to be totally supportive and totally focussed as well
- ALWAYS keep your left shoulder in the centre of the road - imprint this into your memory!
- Don't worry too much about other drivers - those that are not maniacs will give you some space if you obviously look lost or in trouble - no-one will deliberate make life harder for you
It takes about a day of intense concentration to get used to it, but after that it becomes fairly routine. It's likely you will rent a manual rather than automatic - you'll be changing gears with your right hand, which feels weird for a while, but the clutch, brake, and accelerator remain the same.
The other issue of course is whether you actually need a car. There have been times (in Tuscany, Provence, parts of the Netherlands) where I would have liked a car just to have the freedom and convenience, but we always managed with public transport. And parking can be hard in many places - especially anywhere near Old Town precincts.