Secure a new computer | SSH

Secure new computer by creating a new user for the server/computer, then removing rights from root 
 This assumes that this is a new machine and that you are currently signed in as the root user. It works best with Ubuntu Server but still work work to the most part in Mint 
 Add your new user. Lets pretend the user name we want to create is "serverman".

  enter any user name you want.  
 sudo adduser serverman 
 Or If you want to make your own UID: 
 sudo adduser --uid 1362 serverman 
 Check password file. Make sure the user is valid 
 tail /etc/passwd 
 Make user a Super User 
 usermod -aG sudo serverman Check to make sure that your new user is apart of ground "sudo" (super user).  groups serverman 
 The output should show that it is now apart of the sudo group. 
 You could also, try 
 su - serverman 
 That will log you in using that name. now, 
 See if sudo works under new user 
 sudo ls 
 If that worked, Good! 
 Now, log out and then log back in under new user name, serverman (or whatever user name you created). 
 NEXT... 
 Install OpenSSH 
 If you don't have it yet 
 sudo apt install openssh-server 
 lock root access: disable root 
 Go into the ssh config file and change some settings. 
 sudo nano /etc/ssh/ssh_config 
 I like vim as my editor. If you don't know what nano is, look it up. "nano" text editor  
 
 Find and Set PermitRootLogin to "no" add to the file: "AllowUsers serverman" Save and exit. 
 Open a second SSH window. Test to make sure the new user name can sign in. If it doesn't YOUR SCREWED! 
 
 Complete removal (deletes home directory and mail): 
 sudo userdel -r username