Update error

[James Erin]

Hello guys ,facing this error while updating. A beginner and a newbie here so please guide me

===========================
Install Updates Error log
============ Log ===========

Hit:1 http://us.archive.ubuntu.com/ubuntu focal InRelease
Get:2 http://us.archive.ubuntu.com/ubuntu focal-updates InRelease [114 kB]
Get:3 http://us.archive.ubuntu.com/ubuntu focal-backports InRelease [101 kB]
Get:4 http://security.ubuntu.com/ubuntu focal-security InRelease [109 kB]
Hit:5 http://archive.canonical.com/ubuntu focal InRelease
Err:6 http://repo.linuxliteos.com/linuxlite emerald InRelease
  Temporary failure resolving 'repo.linuxliteos.com'
Err:7 https://deb.opera.com/opera-stable stable InRelease
  Temporary failure resolving 'deb.opera.com'
Err:8 http://dl.google.com/linux/chrome/deb stable InRelease
  Temporary failure resolving 'dl.google.com'
Err:9 https://linux.teamviewer.com/deb stable InRelease
  Temporary failure resolving 'linux.teamviewer.com'
Err:10 http://packages.microsoft.com/repos/edge stable InRelease
  Temporary failure resolving 'packages.microsoft.com'
Err:11 https://packages.microsoft.com/ubuntu/18...erver-2019 bionic InRelease
  Temporary failure resolving 'packages.microsoft.com'
Err:17 http://packages.microsoft.com/repos/vscode stable InRelease
  Temporary failure resolving 'packages.microsoft.com'
Get:12 http://net.domain.name/ppa.launchpad.net...pd8/ubuntu focal InRelease
Err:12 http://net.domain.name/ppa.launchpad.net...pd8/ubuntu focal InRelease
  Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
Get:13 http://net.domain.name/ppa.launchpad.net...pps/ubuntu focal InRelease
Err:13 http://net.domain.name/ppa.launchpad.net...pps/ubuntu focal InRelease
  Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
Get:14 http://net.domain.name/ppa.launchpad.net...ook/ubuntu focal InRelease
Err:14 http://net.domain.name/ppa.launchpad.net...ook/ubuntu focal InRelease
  Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
Get:15 http://net.domain.name/ppa.launchpad.net...mpv/ubuntu focal InRelease
Err:15 http://net.domain.name/ppa.launchpad.net...mpv/ubuntu focal InRelease
  Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
Get:16 http://net.domain.name/ppa.launchpad.net...air/ubuntu focal InRelease
Err:16 http://net.domain.name/ppa.launchpad.net...air/ubuntu focal InRelease
  Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
Reading package lists...
E: The repository 'http://ppa.launchpad.net/nilarimogard/webupd8/ubuntu focal InRelease' is no longer signed.
E: Failed to fetch http://ppa.launchpad.net/nilarimogard/we.../InRelease  Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
E: The repository 'http://ppa.launchpad.net/noobslab/apps/ubuntu focal InRelease' is not signed.
E: Failed to fetch http://ppa.launchpad.net/noobslab/apps/u.../InRelease  Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
E: The repository 'http://ppa.launchpad.net/slimbook/slimbook/ubuntu focal InRelease' is no longer signed.
E: Failed to fetch http://ppa.launchpad.net/slimbook/slimbo.../InRelease  Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
E: Failed to fetch http://ppa.launchpad.net/xuzhen666/gnome.../InRelease  Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
E: The repository 'http://ppa.launchpad.net/xuzhen666/gnome-mpv/ubuntu focal InRelease' is no longer signed.
E: Failed to fetch http://ppa.launchpad.net/yannubuntu/boot.../InRelease  Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
E: The repository 'http://ppa.launchpad.net/yannubuntu/boot-repair/ubuntu focal InRelease' is no longer signed.