The instruction page you link to has a sample link which leads to a page containing direct links to mp4 files. However these have https URLs and if you change it to http it reverts to http. This is likely to lead to problems in the Store. I don't know whether it's possible to get a link using http.
Most free website hosts are unsatisfactory because they want to add adverts to your pages to pay for the service, and as they can't do this with media files they often don't support them. If your ISP, who provides your internet connection, provides a website hosting facility as some do, you may be able to use that.
The feed itself is working OK. I can't tell where you've got the original Wordpress feed hosted but there's not need to change it, just change the media file URLs (the media files and the feed don't have to be on the same server).