You can download the newest Ventoy from here. (a link on this page will likely take you to Github for the download)
You'll end up with a file something like 'ventoy-1.0.20-linux.tar.gz'.
If you double click that, you should get a window like this where you can extract or unpack those files. Choose a location like your Desktop (make a new Ventoy folder there) if you want it in plain sight and accessible, or you could make a Ventoy folder in your Home folder to have it available but out of sight for the most part.
Once the files get Extracted, go into your new Ventoy folder (make sure you can see the 'Ventoy2Disk.sh' file).
Right click and 'Open Terminal Here'. If that option isn't available to you in your Linux, open the terminal and navigate with commands to your Ventoy folder.
[Ean or someone, make a post about Terminal navigation and commands, then link it here]
sh Ventoy2Disk.sh { -i | -I | -u } /dev/XXX
Inside those squiggly brackets, the options are -i, -I, and -u. You don't need all of them. It details what each of them means in an image below that, but you likely only need to use -i. Check out the original reference article at the top if you want more details on this command, and these modifiers.
So the code you'd use (including sudo for root access) is:
sudo sh Ventoy2Disk.sh -i /dev/XXX
where XXX is the mount point of your USB such as "sdb"
To load your Ventoy stick with those tasty .iso files….