Hello Jim
And thanks for info - ref France - a lot of their Archives are now on line - and Free - it is the Departments that hold them, so first you need to know where the person that you want to know about comes from , then about what date they were around i then you want the Etat Civil - this gives hatches matches and dispatches and they use the terms
Baptisms marriage et inhume.
This could keep you occupied until you get over, and give you some groundwork.
Best
John