The "-standard" in the image name means that this is a "Standard" Debian
installation, with no Desktop Environment. It probably doesn't have an X
server either, or X fonts, or any of the other things you would need in
order to actually run an X session locally.
A quick web search found a list of the packages on this image:
https://cdimage.debian.org/debian-cd/current-live/amd64/iso-hybrid/debian-live-11.0.0-amd64-standard.packages
As I expected, there is no X server, even though there are a few X
client programs. There's no way you'll be able to start an X session
from this image. It's meant for console/server use only.