Thats a kindle fire you need. You can't watch movies on a ebook reader you need the tablet.
With the fire you just plug in the USB cable and copy them into the video folder.
BTW I have found the fire a quite astonding device. The sound quality makes it a more than good internet radio. The film quality is pretty good and screen size decent enough. The other tablet features are the same if not better than cheaper versions. The twin WIFI pickups do improve the signal quality.
All in all not bad for what you pay for it. Cracking for a flight bag.