GRANT: command not found

[Roberto Pereira Arun]

I am a newbie trying to set up a server for a wordpress website at digital ocean, via youtube tutorial, but something went different in my case, it seems.

History:

I open Putty:
When i insert: mysql -u root -p
I give the right password, but my access is denied.

if i log in normally as root user and THEN use this 'mysql -u root -p' command, i am allowed in mysql monitor with my mysql password.

But, then, mysql does not recognize 'grant' command and also does not recognize 'create' command. It gives me 'command not found' error.

Server version: 5.5.54-0 ubuntu 0.14.04.1

Please, help :\