To get an MCGO IP address for your server, just sign up for an MCGO.io account at https://mcgo.io/register. Then, go to your dashboard at https://mcgo.io/dashboard, and click the Add your server button. 

After you put in your server's name, your computer's IP, and your desired mcgo.io IP address (like play.mcgo.io), it'll be just minutes before you can connect to your server using your new mcgo.io IP address.

Then, make sure you download the MCGO plugin from here, to protect your server from IP changes!