(1) Put a 3d movie with a memory stick or external HD, play the file and turn on 3D with TV
(2) connect DVD/blueray/computer to play the 3d movie, turn on 3d with TV
(3) maybe the simpliest, start youtube app, search for 3d movie demo, select those with split screen left/right, i.e. looks like two same picture putting together side by side, play it, turn on 3D on your TV.
Note: you will need a pair of polarized 3D glass, which is the same one you use in cinemas. There are two come with the TV.