When you're using multilingual support, all language versions of the given document use the same URL (based on the alias path) by default. E.g. the home page has always this URL: /Home.aspx
If you want to see the same page in French, you need to go to: /Home.aspx?lang=fr-fr
Once the language is changed, the selected language is stored in the visitor browser's cookie and when the user comes back to URL /Home.aspx (without any parameter), she is displayed with the French version.
Using custom URL path for different culture versions
If you want the French home page to have different URL than the English version, you need to go to CMS Desk -> Content -> choose the French language, select /Home in the content tree and click Properties -> General.
Check the Use custom URL path box and set the Document URL Path value to: /frenchhome
Now sign out, switch to the English version and go to URL: <web project>/frenchhome.aspx page
The web site culture is automatically switched to French and you're displayed with French version.
You can also find some information on using Wildcard URLs on multi-lingual sites in this topic.