... in my root directory since I dont know what or where that is...
When you log into your web space via FTP, your root directory is usually named 'public_html' or 'htdocs' (it may be different depending on your web host).
If you upload a file to this directory, it will appear in the root of your web site. For example, if you upload a file named 'test.html' to your root directory and your domain name is 'www.example.com', then you will be able to view the file in a browser by going to 'www.example.com/test.html'.
I don't know where to locate my "web servers file structure". I put that query into livebooks search and nothing returned.
The term 'file structure' refers to the files and folders that exist on your web server and their locations (relative to each other), ie. what files and folders are on your web site and where they are.
I don't know how to "create a folder named "webtest in my root directory
If you want your gallery to be in a folder named 'webtest' (for example), then you will need to create a folder named 'webtest' in your root directory and upload your gallery files to this directory.
I do not know what FTP program you are using but if you are using Filezilla, then, once you have logged into your web space and have navigated inside your root directory (usually either 'public_html' or 'htdocs'), just right-click some empty space within the directory, select 'Create directory' and type the name 'webtest'. You can then upload files to this new directory.
If you are having trouble creating new folders in your web space, then your web host should be able to help you out.
Also, if you are not using Filezilla, then please refer to your FTP program's support for details on how to create new folders.
I uploaded 12 images. Six images show up and then the spinning hex.
Please post the URL to the gallery that you are referring to so that I can take a look and hopefully help further.
If the problem is with permissions of the image files or folders, then you should be able to change them using your FTP program (or your web host's online control panel).
Once I see the problem live on your web server, I should have a better idea of what might be causing your problem and how to fix it.
Thank you.