The actual method in creating a server is hard for a... newbie, but a website called Aternos (https://aternos.org)can be used to easily create servers.
Currently, there is no Aetherian mod, so you really can't create... attention. I am currently developing it for the evil sake of attracting attention to myself.
Alternatively, you can use hzon.aternos.me as the IP for the Horizon server, which is a server that has Cube Kid fans. You will not be able to access it; ask HeroicSteve10 about it. I could tell you but I'm tired. He will be more than happy to have someone actually playing on it for once. Even if he's just lounging around in his Netherite gear.