I can tell, when I was living in the US, it was not that easy to meet "real" American people:

they were busy with their own lives, and there were not so many occasions for us to chat, share experiences ....

Here is an amazing website, which I have personally used when I came back to Paris, after spending several years abroad, to meet people, make new friends...

Here is the principle of this website:

Anyone can suggest any kind of event (movie, theatre, picnic, drinks, visits, parties ...)

Instead of going by yourself (alone), you can go with one or many of the interesting and enthusiastic people who share the same interests as you. It's the best way to meet Parisians!

Also each member can register to any event offered by any other member.

It is simple and easy !

..... and members are all French people, willing to socialize, and usually happy to practice their English ^_^

and it is ..... FREE!

http://paris.onvasortir.com/index.php?Langue=EN