how do i make my sister's birthday based of the movie "avatar by james cameron"?

my sister (who is turning 14) wants a birthday based off the movie
"Avatar by James Cameron"
and i don't know how to set it up-i don't know what to do, what events
are going to take place, what decorations i will need to buy/make,
etc.
please help! any advise/info would be greatly appreciated!

-thankyou!
:)