The 10.14.1 you tried to install was an update for macOS Mojave, you need to be running
an earlier version of macOS Mojave fo that to install.
You need to download the full installer app which can be found in the App Store.
The link you used earlier to get that is not broken you need to use your
Safari browser and click on the link, Firefox and Chrome will not work.
Open Safari and click on this link,
How to get old versions of macOS – Apple Support
Go to Check Compatibility to see if your mac qualifies for macOS Mojave.
Then go to the Download OS section and click on macOS Mojave
this will direct you to the App Store Mojave download page,
it should say Get or Download. This downloads Install macOS Mojave.app
to your Applications folder it is 6.2GBs in size and will install
Mojave version 10.14.6, this is all you need.
Before upgrading make a full back up of your Mac.
Check that third party apps you use have updates available for the new OS.
https://roaringapps.com
Check that your printers/ scanners etc have updated drivers and software available for the new OS.
Connect your mac to your router via cable rather than rely on WiFi.
Do not use your mac while it is downloading
and do not use any other devices that share the same internet connection.
If the App Store says ‘Open’ then it is detecting a previous download of the install app
go to the Applications folder locate Install macOS Mojave.app.
Move it to the Trash, empty the Trash.
Restart, click on the link again, the App Store should say ‘Get' or 'Download'.