To add a video just go to Post > Add New.
After placing the title of the video you have to go down to the box where it says options, and you only need to know what each function is for.
Duration: Set the duration of your video.
Video: Place your iframe with the video.
Description: Description of the video.
Download Link: Video download link.
Video Trailer: Short trailer of the video to see in home when you place the mouse over it.
Do not forget to place the Featured image that appears on the right side of your panel, to place the main image.