After you set the 3D plane dimensions in the properties sidebar, you can move on to set the length of the project. Our video will be 30 seconds in length, which means we need 30 seconds x 24 frames = 720 frames.

Go to the Timeline window and set the End frame as 720.

As for the videos we will use as textures, you must look for their durations. If they are less than 30 seconds in length, you must turn on the Cyclic option for the texture. Otherwise, the video will stop at the last frame.

If you have a video of more than 30 seconds in length, you might want to use the Start Frame of your video to pick a range that will give you the best visuals.