file transfer through ftp

[Enzoengine690]

I'm learning how to use Linux. I've set up two Centos 7 virtual machines. I'd like to move files between these two CentOS VMs.
To keep it simple, I log in as root with the same password on both machines. Both machines are pinging each other (network established).
I turned off the firewall on both machines. The FTP package is installed and operational on both machines. However, when I enter the command ftp <ip address of other machine>, I receive the error "connection refused." This has something to do with authorizations.
But if I'm using root as a user, what's the problem? What am I doing wrong?