Birdman is a movie that had its nationwide release in November 2014, so there's a good chance it was already shown at a theater near you.
To check if it's still showing, all you have to do is visit the Google Movies website and search for "Birdman".
Click the link here to get started: http://www.google.co.uk/movies?q=birdman
This will show you the showtimes for your nearest cinema automatically.
Or check out Fandago: http://www.fandango.com/birdman_176140/movieoverview
You need to enter your city, state or zip code to find out where you can watch the film near you.
Alternatively, if you know the name of a theater or cinema chain near you, then you can just visit their website to find out when Birdband will be hitting the silver screen near you.
In the meantime, you can also enjoy this trailer I found on YouTube:
You can also get more information on the official Birdman launch website: http://www.birdmanthemovie.com/
I have to say, this movie looks very funny and interesting in equal measures, definitely worth watching!
There's also a rumour that Netflix are looking to acquire the rights, so if you're patient - it may end up on everyone's favorite streaming service too. Amazeballs!