The latest Ubuntu release, 20.04, marks an opportunity for both LTS users and people on the previous 19.10 release to update Ubuntu and take advantage of the latest features.
Thanks to Debian's upgrade process, it should be relatively simple to either upgrade Ubuntu 18.04 to 20.04 (both LTS) or to upgrade Ubuntu 19.10 to 20.04 LTS Focal Fossa.
Most beginners will find using DVD as Ubuntu installation medium a simplest method. If this is your case use your current operating system to burn the previously downloaded ISO image to blank DVD medium. There are no specific settings you need to choose while burning the ISO image just look for "Burn ISO image" image feature when using your burning software. Alternatively, you can create the Ubuntu 20.04 bootbale installation USB flash drive.
Run your Ubuntu Update
Before you do anything, make sure that your system is already up-to-date. Run a full Ubuntu update and upgrade with Apt.
$ sudo apt update
$ sudo apt upgrade
$ sudo apt dist-upgrade
Then;
$ sudo apt install update-manager-core
Then;
$ sudo do-release-upgrade
Then;
$ sudo do-release-upgrade -d
Now you are ready to upgrade to 20.04 from 19.10!
If you currently have Ubuntu 19.10 and you would like to upgrade to 20.04 then you are in for a treat! Follow the commands in your command line below.
sudo do-release-upgrade
sudo apt update
sudo apt upgrade
FINAL UPGRADE STRING
sudo apt update && sudo -y dist-update