Ubuntu 20.04.1 was released on August 06th 2020, but is not available to be upgraded for 18.04 users (until today - Sep 30th). That was a really long wait (I've been a bit frustrated, to be honest), but now it is here.
So, to upgrade to 20.04.1, just doing these simple steps:
1. Upgrade the installed packages of Ubuntu version 18.04
$ sudo apt update && sudo apt upgrade && sudo apt dist-upgrade && sudo apt autoremove && sudo apt autoclean
2. Upgrade Ubuntu
$ sudo do-release-upgrade
Note: just type "y" & Enter if asked.