Install Virt Manager on Fedora
I show the beginners version of a Virt Manager install for Fedora or Nobara Linux. Fedora makes this very easy with a package group....

Virtual Machine Manager is an excellent option for using virtual machines on Linux. QEMU and KVM make a great combination for virtual machines and Virt manager is great to tie everything together.
Video Version:
Getting Started
First, before installing anything, virtualization needs to be enabled. To do this reboot the computer and go into the BIOS. This is generally done by a function key or Delete key. For my machine it was F2. If in doubt, search for your computer or motherboard manufacture's bios key.
Once there, locate the option for virtualization. I tend to find this under the Advanced menu, sometimes it's in a sub-menu. If in doubt, look up where this would be by searching for the computer/motherboard manufacturer's BIOS guide or possibly just look for their virtualization option.
If virtualization can't be enabled, go ahead and sign into your system, and open a terminal then skip to the install step.
If virtualization could be enabled, continue here. Boot the computer and sign in like normal.
Once fully signed in, start a terminal and run the command below:
egrep '^flags.*(vmx|svm)' /proc/cpuinfo
Ultimately, you should see some text come up (not command not found). If you don't see any result (just the next line) then it's likely vritualzation wasn't enabled. It's worth double checking your changes saved in BIOS or looking up if your CPU supports virtualization.
If all is set here, proceed to the install steps.
Installing Virt Manager
Fedora, and thus Nobara, has a virtualziation package group. This makes installing the required packages very easy.
Open a terminal, if one isn't already open, and run the command below to install the mandatory and default packages:
sudo dnf install @virtualization
If you prefer, you can also install the optional packages via this command:
sudo dnf group install --with-optional virtualization
Here are a list of packages that are included:
Mandatory Packages:
virt-install
Default Packages:
libvirt-daemon-config-network
libvirt-daemon-kvm
qemu-kvm
virt-manager
virt-viewer
Optional Packages:
libguestfs-tools
python3-libguestfs
virt-top
You'll have to follow the prompts like normal for any other install.
Enable libvirtd and add user to the group
Once complete, you need to start and enable the libvirtd service. To run virt manager without root privileges, add the current user to the libvirtd group, this isn't required, but the root password will be needed every time virt manager is started.
sudo systemctl start libvirtd
#sets the libvirtd service to start on system start
sudo systemctl enable libvirtd
#add current user to virt manager group
sudo usermod -a -G libvirt $(whoami)
Run the app
Virtual Machine Manager should show up in the application menu. After launching it, I selected local iso. Then clicked browse on the Choose ISO or CDROM install media then clicked "Browse local" in the bottom left.

Select the ISO file, if it's a fairly standard Linux distro or Windows version, the checkbox can be left checked for "Automatically detect from the installation media/source". If it's a non-standard distro or beta, then uncheck the box and start typing to try to find the closes option to ISO or image being used.
Click "Forward."
Determine how many CPUs and how much RAM to provide the virtual machine.

Once compelete, click "Forward"
Determine where the storage will be for the virtual machine. Keep in mind this can be stored on the current system drive or a new hard drive.

Click "Forward"
Name the virtual machine and confirm options before clicking "Finish."

Next Steps
From here, the install for the selected ISO or image should be run as normal. It's important to note when selecting the hard drive to install on, the only hard drive provided will be the virtual drive that is setup. Nothing beyond the selected drive/size can be used.
In my case it said "Virtual Drive" and that is how it was easy to tell I wasn't installing over my standard Linux system.