Hi @taek8461 once you configure xorg/hdmi as shown here: Debian: Getting Started with the BeagleBone Black
Make sure to install, fbdev driver and xrandr utilities:
sudo apt update
sudo apt install read-edid xserver-xorg-video-fbdev x11-xserver-utils
#/etc/X11/xorg.conf
Section "Monitor"
Identifier "Builtin Default Monitor"
EndSection
Section "Device"
Identifier "Builtin Default fbdev Device 0"
Driver "fbdev"
EndSection
Section "Screen"
Identifier "Builtin Default fbdev Screen 0"
Device "Builtin Default fbdev Device 0"
Monitor "Builtin Default Monitor"
EndSection
Section "ServerLayout"
Identifier "Builtin Default Layout"
Screen "Builtin Default fbdev Screen 0"
EndSection
Then feel free to install any of the linux window managers…
Regards,