There are certainly much better tutorials. This is here mainly for me to be able to repeat various task when ir eceive new Linux server.

Some tasks that can be done:

1. df -h;free -mht;w;passwd;
2. vi /etc/ssh/sshd_config
uncomment line with port 22 and change to non standard number of your choice, like 14444
3. apt update;apt upgrade;apt install whois htop nmon nload glances denyhosts 2>/dev/null||yum update;yum upgrade;yum install whois htop nmon nload glances denyhosts 2>/dev/null;
4. reboot
Login again at newly set SSH port.
5. Install Wireguard and enable port forwarding.
6. Install OpenVPN
7. setup logs removal.