@80sMum
I hope the OP doesn't mind me sharing my own experiences on her thread.
A few times I've hired a car, while travelling with my DS who's still too young to drive, and can't yet reliably read a map, so as good as being on my own. Car hire companies will give you instructions on how to find them - most recently was last month in Iceland when we got a shuttle bus to the car hire office. Both were clearly sign-posted. I'd asked for a Toyota as I've had that make of car before and reckoned it would be easier than a make I was totally unfamiliar with. Every time I've hired a car I've checked out the route on google maps in advance so I've got a good idea of where I'm going and how long the journey will be. I've always arrived and picked up the car in daylight, but I think if my flight got in at night, I'd stay close to the airport overnight, then pick up the car in the morning rather than try driving in the dark.
My tip for driving on the other side of the road is to forget about right and left, and just remember that you, the driver, should always been next to the centre line.
If I've not hired a car, then I've usually booked a shuttle bus to my hotel or close to it, or got public transport. Airport websites usually provide information on transport options to and from the airport, which let you plan ahead. If I'm going to be using public transport, then I book accommodation which is close to transport links.