Ubuntu Noble Numbat
This has not been tested, it's a placeholder for the August 2024 release of Ubuntu 24.04.1
To start, read the official release notes.
If your install fits into "vanilla Ubuntu plus maybe a handful of 3rd-party repos", then this guide for a simple upgrade to Ubuntu 24.04 "Noble Numbat" from Ubuntu 22.04 "Jammy Jellyfish" can be helpful. 3rd-party repos are handled with a find command.