I don't find driving in Paris that bad, but you do need to be used to European driving.

To navigate, you need to know the layout of the main squares of the city, as all signs are based around them. Or... Use the quays. There is an expressway that runs the length of the river (part closed on some weekends and summer days). This is an easy and fast way into and out of the city - even if it doesn't quite take you towards Caen (but it will take you to the Périphérique).

The logical way from the city centre towards Caen is along the Champs Élysées. This takes you to the Étoile (the square around the Arc de Triomphe). If you go this route, USE THE AVOIDING TUNNEL. I can't stress this enough. If you don't, you will be among the worst traffic in France (there is a persistent rumour that French insurance specifically excludes accidents on this square).

Driving round the Parisian squares is an art in itself. You kind of edge towards your exit, going anti-clockwise where you can, respecting the space immediately in front of others. It kind of works, but don't expect priorities and traffic circle style flows.

In general, treat traffic lanes as a fluid concept.

If you need to drive on the Périphérique, then the one rule to remember is that joining traffic has priority over the inside lane. You should also know the name of the gate 'porte' you are exiting at, although the main motorway routes aren't badly signed as long as you know the principal destinations on them.