How to use different language on the same website

Hello ,
I use the imagestore plugin correctly with the french langage (it’s easy to install).
Now, i wish to make a page in English , Deutch , …. For foreigners, and i would like to use the langage appropriate.
The english one on the english langage , the Deutch one the deutch page , the spancih one ….

So how to do that ? Should I creat one subdomaine with WP and Imagestore each time I want to use a different langage ???
Or could i just find a way to select the good langage for the good page ?

Thank’s