From outside the network, which is where I am guessing you are trying to access from, I personally prefer to connect via FTP, which creates a direct connection. I do not like to install WD software, which uses a relay service going from your outsde machine to their relay server and then to your network.
To setup FTP, you’ll need an ftp client software installed on the remote machine (FileZilla is an excellent free ftp client). You’ll need to forward the ftp port (port 21) from your router to the NAS’s IP address (assuming Verizon FiOS is not your ISP - they block port 21 in may areas so you’d need to use a different port than standard port 21). While doing port forwarding it’s also best to assign a fixed IP on your router for the NAS…that way the IP won’t change if My Cloud is rebooted. Otherwise, with the IP change, you’d need to update the port forwarding again. All the router changes can be done usually via the router’s web interface. If you have a second router hooked to your ISP’s router, you’ll need to forward the port from ISP router to 2nd router and then go into the admin of the 2nd router and forward the port to the NAS. The idea is someone connecting on port 21 will go straight from outside to your NAS via your router(s). Once this is setup, you can connect via ftp remotely using the ftp client using the usernames and passwords for the shares that you’ve already set up.