[Koha] Location to store text files and images in Koha

[Jack Boulier]

I am sure that this question has been asked a thousand times, but I am unable to locate an answer in the archives, or I am seeking the answer with the wrong terminology. 
I want to have links on the home page that retrieves the web page and displays to the screen. I am able to call the links to display information from a separate server, and have the text files display when hosted on a second server. But cannot locate them when hosted on the same server.
I need to be able to store files on my local Koha server to be accessed from the Koha Home page. I don't know how to get the OPAC NAV to find the documents using http://localhost/path/document
I want this to be a permanent location so that updates to the software do not over written the files each time. I would also like to display images of new acquisitions on the home page.
Any help would be appreciated.
I am using Ubuntu Xenial and Koha 17.11.03. The other features of Koha work correctly/
Thanks,Jack