how to create a dual language website?

Hi,everyone, i want to create a dual language website using wordpress.
the specific description of the website should be:
on the homepage, there are 2 buttons for language choice (just like the citizenship and immigration Canada official website), one for English, and the other is for France, whatever button people click, they will enter the version of website they want.
my problem is, how can i create that 2 buttons on my homepage? if anyone knows?

thanks!