Cherbourg
Cherbourg on a Sunday is no problem.
You may have difficulty purchasing fuel but the aeroclub are usually open and will dispense fuel for you. Just make sure you have sufficient euros to pay them in cash.
To save yourself any embarrassment ensure that you inform French customs of your intended arrival. That will almost certainly mean that nobody will be there to greet you but that's 'pas de probleme' as the French would say!
ATC may well be operating for the local aeroclub on a Sunday and at Cherbourg almost always speak impeccable English.
The French circuit calls are no more difficult to learn than English ones and follow exactly the same pattern ie. who you are, where you are & what you want.
I have a handy print-out of the french phrases on my knee board around a drawn circuit and that serves just fine. Usually, after the first call in my version of French ATC reply in English.
Flying really is a lot more relaxed in France you know.