Eating out in France, especially outside the big cities, is a bit different from the UK. Some British people seem to have problems in understanding the system of menus. A menu in France is a fixed price meal, of three, or more courses. You can choose any one of the first courses, plus any one of the main courses, plus any one of the desserts; if there are more courses you choose any one of the alternatives in the same way. The price you pay is the price of the menu, irrespective of which dishes you choose. So if the menu is 15 euros, for four courses, and you have no wine or mineral water, 15 euros is what you pay. By law, all restaurants must offer at least one fixed price menu, where the price includes tax, service, bread and tap water: apart from other drinks you pay nothing more, and a tip is not expected.
Most restaurants will have at least three menus at different prices. They are always good value, and can often provide a good way to try new dishes. What in the UK we call a menu is called the Carte in France, and you can order what you like from it. However, this will cost more; three dishes from the carte will be more expensive than the same dishes as part of a fixed price menu.
It is a good idea to have a reasonable dictionary or phrase book, because there are many things that you may not recognise. Some, such as museau de porc, you may not want to try (it's pig muzzle), whereas many will be wonderful if you know what they are, even approximately. There is a small but helpful book called "Eat Your Words".
Meals in France are a crucial aspect of the culture. Everywhere, including many supermarkets, closes for about two hours at lunchtime. Everyone expects to get home for a substantial dinner in the evening. Meals are formal, and from a minimum of three to up to eight or nine courses. All the schools, even the infants, display the menus for school lunches for the next couple of weeks outside, so that parents can check what their children will be eating; three course, no choices, every day.
What this means is that meals are only available in restaurants from around 12 til 2, and 7 til 10. If you want to eat in between, buy the raw materials (charcuteries sell pates, hams, cheeses, quiches, salads and if they are also traiteurs, prepared dishes to reheat) or look for a Brasserie which normally provide simple dishes most of the time.
Food is important to the French, and choosing the dishes to eat is a significant part of the process. Meals can take some time to eat, and dishes are served with intervals in between: speedy service is a sign of a bad restaurant.
The French have no understanding of the concept of vegetarianism, any more than Muslims have pork recipes or anyone except a few rabbis understands kosher rules. If you have to be vegetarian, learn a few key French vegetable based dishes, and ask for them even if they are not on the menu - they might be prepared specially.
It's a bit of a cliche (and a bit of a cliche to say it's a bit of a cliche) but the French live to eat, not eat to live like the British. Food is sacred stuff, meals are rituals, and junk anathema. What the cholestorol groupies call the 'French paradox' is that the French diet breaks all the rules for cholestorol and fat, but the French are healthier and live longer than we do. Part of that is that they do not eat snacks between meals, nor do they gobble choclate bars and other sweeties. A croissant for breakfast, two good serious meals, and that is it. The diet is balanced over a week rather than by meal, and they do not eat more than they need. The idea that a meal is special occasion, when everyone sits down at a table, with proper cutlery, is sacrosanct.
I went to a vide grenier (empty the attic) which is a bit like car boot sale, in a small village recently. At around one o'clock, everybody began to clear a space on their stall, or setup a little folding table. They laid out a plate, cutlery, a glass, and made a meal with perhaps salads, charcuterie, cheese, a quiche, accompanied by bread and wine, even if they were on their own. Civilised, is it not? And the French word for 'mate' is 'copain', ie. co-pain, the person you share your bread (pain) with.