Set no password on setup

When I loaded Linux, I forgot to add a password. I just hit enter and passed the password screen. I want to add a password to my user account, but I cannot change/add the password. When I try to change the password, the system states that the password was updated; see below. However, on boot, it fails to request a password.

root@dennis-VivoBook-ASUSLaptop-X512DA-F512DA:~# sudo passwd dennis
New password: 
Retype new password: 
passwd: password updated successfully

Thank you
Dennis