Now you know how to add a user. It is time to learn about passwd command. Following are common things.

Change user password for rocky
Code:
passwd rocky
Force password change at next logon
Code:
passwd -f rocky
Nullify password (aka delete password)
Code:
passwd -d rocky
Use above only if you need password less account

Disable account / Lock account
Code:
passwd -l rocky
To enable disabled / locked account, assign a new password
Code:
passwd rocky
List user password aging
Code:
passwd -s rocky
Force aging - minimum number of days before user are allowed to password
Code:
passwd -n 30 rocky
Force aging - maximum number of days a user need to wait between password change
Code:
passwd -x 90 rocky
Read man page for more options and info
Code:
man 4 passwd
man passwd