2012 Mini, how to update to Catalina/Mojave

Hey everyone! Sorry if I posted this in the wrong area; im new and just got my first Mac (Late 2012 mini, Core i7)

It came with 10.9.5 installed. I know it can go as far as MacOS Catalina, but I cannot find how to do so. The App store doesn't show any updates.

I found a page on Apple about old OS' but when I click any of the links it just opens the App store (or iTunes, but that says this isnt avilable in the US store)

I'd like to go to Catalina, or at least Mojave) but I just can't find how to do so.. Thanks for any help!