It hasn't always been this way, but hosting a Minecraft server has gotten much easier than it used to be, and this remains the same for Minecraft 1.18.

Minecraft: Java Edition 1.18.1 is now rolling out with its usual fix and a patch for the security flaw. All players should download this patch as soon as possible, while game server hosts may need ...

Minecraft runs on Java version 17 as of this pre-release – and you can expect the same to be true of the live version of Java Edition once 1.18 officially lands.