From your screenshot it is clear that Calibre and your reader are not connected. When they are connected, you will see a Device icon in the Calibre top menubar. At the time that you took this screenshot, had you clicked "Connect" on your Kobo after connecting your cable, and was the Kobo showing up on your desktop? Have you set up Calibre to connect and transfer files to your Kobo? (Go to Preferences and click "Run Welcome Wizard" down the bottom.)
One other thing to try is to start the Calibre content server (Connect/Share > Start Content Server). Then click Connect/Share again and note the IP shown there (third line, includes a port number). Then go to the Kobo's browser, and type http://IPnumberhere:Portnumberhere
. When the page loads, click on the "epub" button next to the book you want.
If you've done all this and nothing works, I again suggest posting your question in the Calibre forum, including all details including app version numbers, screenshots, and all details of what you've done so far.
I double checked and made sure there were no DRM infested files
Can I double check with you exactly how you did that? Since your issue is unclear right now, it's worth double checking everything.
I dont understand if people have paid money for ebooks in the past, why would they not be able to just easily install them on this reader???
Many of us have had no trouble installing them. Your problem is atypical. People here are willing to help.