What you need first
An account and a confirmed email address. Confirming is not a formality: without it you cannot create an instance, because otherwise one throwaway address a minute would get a server.
Creating it
- In the dashboard go to Servers, then New server.
- Pick a template. Paper is the standard for plugin servers and the right answer when you are not sure. The description under each entry says what the template is for.
- Pick a version. We fetch the list live from the vendor. Versions that would not start on our Java are not in it at all.
- Name it, set RAM and disk. Both are capped by your plan, and the field will not let you past it.
- Click create server. The first 30-day term is paid from your balance at that moment.
The instance then reads installing. The node downloads the server software, verifies its checksum and writes the configuration. Forge and NeoForge run an installer once during this, which takes a few minutes longer than Paper.
Starting it
Once the instance reads offline, it is set up. Press start, then watch the console. On the first start Minecraft generates the world, which takes a moment depending on version and settings.
Java servers need you to accept the EULA once on that first start. How to do that is in the files guide.