This is a brief checklist of operations to conduct after a fresh installation of Qubes. Full documentation is available at https://www.qubes-os.org/doc/updating-qubes-os/.

After configuring your network first update the dom0:
sudo qubes-dom0-update

Next, update your TemplateVMs: Qubes Menu > System Tools > Qubes Update.

The Qubes Update utility doesn't always work the first time for me. If you find it hangs and produces no details launch the TemplateVMs individually and from the command line run:
dnf update
for Fedora and
apt-get update
for Debian.

Now reboot to effect any kernel updates and load the updated dom0 environment.

Install critical software that you will definitely need to your TemplateVMs. Things like:

• screen
• sshfs
• nmap
• links/lynx
• nano
• whois
• bind-utils (fedora) dnsutils (debian)

Next, duplicate the default fedora and debian TemplateVMs and update your personal, work etc AppVMs to rely on the copies. Since system Qubes like sys-net and usb rely on the default fedora TemplateVM you may regret making changes directly to it when setting up your regular working AppVMs.

Software I like to install into my duplicated TemplateVMs includes:

• kde-standard
• kate
• chromium (part of default repos) or google-chrome (third party download)
• telegram-desktop

It is prudent to check your repositories for meta packages that install bundles of packages which might otherwise leave a system piecemeal and produce unexpected dysfunction. For example, it is possible to install kate by referring to it directly. However if your intention is to have a fully functioning KDE environment rather than just the essential packages required to install and run kate you are liable to find yourself in trouble if you end up trying to use a KDE function that either didn't or relies on a package that was not part of the dependency tree you initially installed.

On Fedora and Red Hat descendant images you can pull up a list of such meta packages or "package groups" by running (as root):
# dnf grouplist Last metadata expiration check: 0:19:25 ago on Tue Jun 13 04:20:04 2023. Available Environment Groups: Fedora Custom Operating System Minimal Install Fedora Server Edition Fedora Workstation Fedora Cloud Server KDE Plasma Workspaces Xfce Desktop LXDE Desktop LXQt Desktop Cinnamon Desktop MATE Desktop Sugar Desktop Environment Deepin Desktop Budgie Desktop Development and Creative Workstation Web Server Infrastructure Server Basic Desktop i3 desktop Available Groups: 3D Printing Administration Tools Audio Production Authoring and Publishing Budgie Budgie Desktop Applications C Development Tools and Libraries Cloud Infrastructure Cloud Management Tools Compiz Container Management D Development Tools and Libraries Design Suite Development Tools Domain Membership Editors Educational Software Electronic Lab Engineering and Scientific FreeIPA Server Games and Entertainment Headless Management LibreOffice MATE Applications Milkymist Network Servers Neuron Modelling Simulators Office/Productivity Python Classroom Python Science Robotics RPM Development Tools Security Lab Sound and Video System Tools Text-based Internet Window Managers Qubes Environment Qubes UI (Audio/Gui)
Then one may install such a group thus:
dnf groupinstall "KDE Plasma Workspaces"

It's a good idea to install the latest TemplateVM images. You may like to experiment with updating your critical system VMs (i.e.: sys-net, sys-usb) to use the latest fedora template. I personally would advise duplicating freshly installed images, just as with those installed from the installation media, before making any base modifications - including package updates. sys-net can generally be expected to run smoothly off a fresh image, after all. From the offical documentation at https://www.qubes-os.org/doc/templates/:

# qvm-template list --available Available Templates debian-10-minimal 0:4.0.6-202010131933 qubes-templates-itl debian-10 0:4.0.6-202009131420 qubes-templates-itl debian-11-minimal 0:4.0.6-202302031359 qubes-templates-itl debian-11 0:4.0.6-202302031359 qubes-templates-itl fedora-32-minimal 0:4.0.6-202010191916 qubes-templates-itl fedora-32-xfce 0:4.0.6-202010191916 qubes-templates-itl fedora-32 0:4.0.6-202010192324 qubes-templates-itl ... fedora-38-minimal 0:4.0.6-202305201231 qubes-templates-itl fedora-38-xfce 0:4.0.6-202305200036 qubes-templates-itl fedora-38 0:4.0.6-202305200036 qubes-templates-itl

To gain access to the official community repository of templates affix:
qvm-template --enablerepo qubes-templates-community list --available

Then install your preferred templates thus:
qvm-template install template-name

The GUI tool qvm-template-gui can be used in later stages to rapidly reassign AppVMs their updated templates but at present has no facility for browsing or installing new images.