Lot of confusion how to install, please help!

[Vasco]

Read this please:

How to install CoreELEC

Update Please follow the more recent installation guide on CoreELEC Wiki New installation Prepare an SD card (class 10) / USB flash drive as follows; NOTE: On some devices, only 1 USB port is able to boot the device, you may have to try them all to see which one works for you, some boxes are also unable to boot from a USB drive. Download the latest .img.gz file from here. Use Rufus, usbimager (or your preferred image writing software) to burn the downloaded image file to your SD card / USB…

Yours is a S905x3 With 2GB ram so just chose dtb for that one.