Publishing to our Intranet (SharePoint)

Hi I seem to be part way there and following @owen Holt's explanation but am missing something.

Using Office 365/sharepoint 365

1. Created a sharepoint site

2. Got all the published (as web) files uploaded into a library

Then I get stuck with this step:

4) Right-click on the story.html file in the document library to get the link

I've right clicked and gets me a "share link" - same link you could email someone.  I've also tried via the windows explorer but then I get a "c:\users\paul\link"

I then did a right click and under One drive for business got a link https://XYZ.sharepoint.com/sites/PaulTestSite/Course%20Test/index.html?web=1

So the 2nd I know isn't right.

It seems like the first one would be

Taking the first one I then create /edit a page

5) On your Sharepoint page, add a new web part, "Page Viewer Web Part". In the tool pane, you paste the link to your story.html file. If you're proficient in HTML, you could also embed the code in a Content Editor Web Part

-- The interface has some of this - but basically I've added a link to the "html" file (the third one -https://XYZ.sharepoint.com/sites/PaulTestSite/Course%20Test/index.html?web=1) 

When the link is clicked on - then the file is downloaded (doesn't matter if using IE or Chrome or...)

So either 

1. Link isn't right (which it is linked)

2. or something else to have it trigger and load the HTML page and relative folders/links content etc.

I also tried the "embed" option - and that judges the Iframe as invalid - it recognizes the link isn't right.

(oh I tried changing the file to aspx and clicking on that says file not found - suspect it is looking for file names no longer or...)

Any ideas ??