If you don't want to use presentation software, you can turn off the player, put image, video, and audio files in the root folder of your SD card (or other storage device) without a presentation script, and then turn it back on. These files will then play alphabetically as a looping playlist.
This option has significant limitations:
There is no control over output resolution/rate
Scheduling is not available
There is no storage management, which will wear storage more quickly
There is no control over image duration (always 6 seconds), transitions, or scaling
You cannot control media playback order except for (re)naming files
There are no checks for media compatibility which can cause poor playback and reboots.
If this playback method isn't working:
Make sure that there isn't an autorun.brs or Autoplay file (Autoplay.xml, Autoplay.bsp, Autoplay.csv, autoschedule.txt) on the storage device.
Check that the media files are in the root folder of the storage device (for example, "SD:\").
Make sure that you are using image, video, or audio content that the player supports. You may need to set your PC to show file extensions to ensure that the media extensions of your content files are supported.
Verify that images are no larger than 1920x1080. If images are too large, they'll fail to display.