If you want to change your world name and make sure that is the one you always load into, you can follow these instructions below:
- Log in and go to your dashboard here.
- Select the server you want to change and hit the Activate button to start your server.
- Once your server has started, go to the Settings tab from the top menu.
- Go to Level Name and add your new name here, click save.
- Restart your server and you're done!
Be sure not to include any spaces or special characters in your name as it will cause issues if you need to download it.