The command:
sudo apt update
doesn't work. The output of this command is the next image.
That ppa has zero files in it. It's had zero files in it for a long time now. Unfortunately there's a lot of documentation pointing to that PPA online, so many people have it enabled with no benefit. The PPA itself even says it's discontinued. In short, remove that PPA.
https://launchpad.net/~webupd8team/+archive/ubuntu/java