Have Fedora Cosmic Atomic. I have a new SanDisk Flash Drive. Have current ventoy download 1.1.17. Extracted file. Tried to install VentoyGUI.x86_64 I think. Tried with many codes from searching. I have many screenshots of what I did. I cannot install Ventoy at all. Worked over a hour plus. I would like to add my ISO’s to Ventoy. Still very new at linux. But this is bugging me.
I would download the ventoy-1.1.17-livecd.iso from here. Burn it to a usb device and you should be good to go.
Are you trying to set this device on fire or something 
Of course!
Burning to a usb device is the same as burning to a DVD or CD is it not?
Using the same tools to do both implies the process is the same.
I associate “burn an iso” with “writing with a cd/dvd/bd writer” onto a CD-R/CD-RW (and similar) but certainly not writing to an sd card or usb flash drive. There latter does not use a laser.
</pedantic mode> 
There are too many errors to retype manually, some from not following instructions, but dnf appears to be missing which suggests either a bad PATH setting or corrupt filesystem.
Please post terminal output as web-discoverable pre-formatted text selecting and pasting using the <\> button.
# 1. Move to the directory where the file was saved.
cd ~/Downloads
# (If you saved it elsewhere, use 'cd /path/to/your/directory' instead)
# 2. Extract the Ventoy archive
tar -zxvf ventoy-1.1.17-linux.tar.gz
# 3. Enter the extracted directory
cd ventoy-1.1.17
# 4. Launch the Ventoy Web interface
sudo ./VentoyWeb.sh
Once the command runs, open your browser and go to http://127.0.0.1:24680 to access the Ventoy UI. Refer to the README file inside the extracted folder for detailed options.
I really do not understand why more and more users tend to rely on inaccurate info from search assistants, even though the software developers provide extensive documentation on their website?
here we go Linux GUI . Ventoy
But there are also reports of drivers driving into a canal because their GPS told them to. 
Thinking about using the ISO Image Writer and getting a new version. Cosmic Atomic is junk. Although scared about doing it considering my problems installing Linux the first time.
cosmic is a quite new DE, so maybe not the right choice if you’re at the beginning of your linux experiance.
Atomic distributions are very restricting as well. It depends on what your requirements are. It’s probably easier to start with a traditional fedora version first and learn from the mistakes you’ll make along the way.
Multiple ISOs may be stored on a USB attached NVMe SSD. Multiple instances of an installed Linux distro coupled with a unique GPT UEFI ESP partition can also exist on this same USB SSD. In the end, any one of the ISOs or installed Linux distros can be booted as desired.
This “magic” happens when making use of the open source “Ventoy” solution:
The maintainer has requested the public to utilize the following download link:
Download and unzip into a free directory on a USB SSD
Install Ventoy on a second USB SSD
########################################################################
# Install or Update Ventoy
########################################################################
# Change ( sdX ) to use an appropriate USB drive letter such as ( sdc )
# Options { -i | -I | -u }
-i install ventoy to sdX (fail if disk already installed with ventoy)
-I force install ventoy to sdX (no matter installed or not)
-u update ventoy in sdX - do not touch other partitions
-l list Ventoy information in sdX
########################################################################
# sudo -s
# ALL partitions and data will be lost during an "-I" INSTALL.
# ALL partitions and data will be lost during an "-i" INSTALL.
# Data partitions will have to be formatted and named
########################################################################
# Mandatory partitions created on the USB SSD:
# 1st partition - VenToy_nn_ISOs - Store ISOs here
# 2nd partition - Ventoy partition - do NOT touch
#
# Space for optional manually created partitions:
# UEFI ESP partition(s) - should follow the Ventoy partition
# OS partition(s)
# Data partition(s)
########################################################################
# Example 115 Gigabyte USB - L VtoyF_99_ISO_101
( date;./Ventoy2Disk.sh -i -g -r 105678 /dev/sdc;date )
( date;./Ventoy2Disk.sh -I -g -r 105678 /dev/sdc;date )
########################################################################
# Example 894 Gigabyte USB - L VtoyK_99_ISO_894
( date;./Ventoy2Disk.sh -i -g -r 888000 /dev/sdc;date )
( date;./Ventoy2Disk.sh -I -g -r 888000 /dev/sdc;date )
########################################################################
# Delete or Rename log.txt after initializing a USB stick
########################################################################
# Windows users should create a bootable SystemRescue USB to gain access
# to gparted. Use gparted to format and name the ISO parttion and to
# create/format additional partitions as desired.
########################################################################
#
Tips below concern filesystem selection during a Linux install:
The anaconda installer will NOT install if the target partition contains a Linux OS. Blivet may be used to delete the partition but WILL allow you to delete a partition other than the one intended. It would be much safer to use the gparted partitioning utility to format the desired partition BEFORE attempting to install Linux.
Btrfs, the default filesystem for Fedora Workstion, is on a different level compared to Ext4. Ext4 is a “pure filesystem” while Btrfs has disk and volume management built-in. This wonderment is OVERKILL when Linux is installed on a USB SSD, If your use case does NOT require spanning the OS over multiple disks select the custom install option and change the selection of “btrfs filesystem” to “Standard Partitioning”. Overlooking this option may lead to angst later on.
When I recently used Ventoy again (after 2+ years on not using it), I just blindly followed the instructions (for installing Ventoy on my USB drive) from the Ventoy website and instantly forgot those instructions. I had issues later in what I was trying to do (so those are the parts I remember, not the easy parts). I don’t even remember whether I used Ventoy2Disk.sh or VentoyGUI_x86_64. I’m sure either works.
When you tried that, you had forgotten to cd to the directory containing the extracted ventoy, so ./VentoyGUI_x86_64 can’t work when you aren’t where that file is.
That cd was one of the instructions in the list of instructions I blindly followed.