The simplest solution would be to install Debian. The thing to note is that the Debian installer is designed to be multipurpose so it will default to installing a GUI.
Assuming you can boot off of a live USB with the Debian installer, you can follow the steps until you get to tasksel software selection from there uncheck gnome and check system utilities and ssh server. Also Debian defaults to separate root and user accounts. I would recommend disabling root (see steps below)
On a different machine, ssh into the server (I'm using debian.local but you should replace that with a hostname or IP)
ssh username@debian.local
Once you have access run the following commands to switch to root.
su -
Install sudo and give yourself access
sudo apt update
sudo apt install sudo
sudo usermod -aG sudo username
Now type exit twice to exit the shell entirely. Once that's done log back in.
ssh username@debian.local
Lock root
sudo passwd -l root
Now you have a system to set things up. I would start by enabling automatic updates and installing docker compose. (Docker compose allows you to deploy software very quickly in co trainers via a yaml spec)
#enable automatic updates
sudo apt install unattended-upgrades
sudo dpkg-reconfigure unattended-upgrades
sudo systemctl start unattended-upgrades #probably not needed
#install updates and install docker and docker-compose
sudo apt update
sudo apt upgrade
sudo apt install docker.io docker-compose
sudo systemctl start docker
sudo usermod -aG docker username
You will need to log out and then back in to apply the docker permission.
I hope that gets you started.