Debian 10 I install only printer deamon and utilites, then install:
apt-get install aptitute
aptitude install xorg openbox
And i do manually login and starting
startx
How to start openbox on power on? (xdm no need, it not must required enter login/password)
You need display manager like:
Use LightDM and see manual to configure automatic login https://wiki.ubuntu.com/LightDM