iptables -L -nv
This outputs your firewall configuration.
yum install nmap
This installs the tool nmap, which is a powerful port scanner, very useful.
nmap -Ss -O 18.104.22.168
nmap -O 22.214.171.124
These commands scan the computer at IP address 126.96.36.199. The -Ss is looking for open TCP ports and the -O tries to identify that computer's operating system and version.
Anyone have any idea what these commands mean and what type of action I should take on the server?
You need to immediately contact your hosting service provider and see if their sysadmin staff are responsible for these commands being run on your server. If they are positive that it was their doing, you can ask them nicely to inform you in the future when they use root on your system, but everything's OK.
If the hosting service provider tells you that none of their staff have executed commands as root on your system, you need to inform them that the system was hacked, and then either get them to help you restore it to a known good backup made before the system was compromised, or (preferably) burn it to the ground and rebuild it from scratch.
Never use whatever you were using for root password on this system for anything, ever again.