firewall-cmd
Using CentOS firewall daemon can help secure your server. This might help protect you from data theft, and unwanted server access.
CentOS 7 basic modifications (lnmp)
Here are some basic CentOS 7 modifications for Linux nginx MariaDB PHP.
Use your favorite editor when editing files. I prefer vim, but if you want to use nano or some other please do that.
DD and PV
If you want to backup a disk or just copy disk to new source dd is the command to do this.
PV(Pipe View) is a good tool to show progress of transfer, but to use PV we might need a size so the % is correct.
Help finding commands
There are to commands that might help finding the commands you are looking for.