Travelers from the United States, the U.K., and all EU countries do not need visas to enter French territory. A regular passport is sufficient. Travelers from countries within the Schengen Zone don’t even need to show passports.
Just be ready to explain travel plans and offer proof of an exit ticket. Immigration officers can ask for this information at their discretion. Always better to be prepared in case something looks out of order to the immigration officer processing your entry.
Travelers planning to stay in France for more than the 90 days granted to tourists have to apply for visas. This process requires the approval of the French foreign consulate. For that reason, visa applications to France usually begin with petitions to that traveler’s local French consulate.
For more information on the visa process, check out the French government’s visa site.