Calibre with Raspberry Pi 4

I noticed a post regarding the installation of Calibre on the Raspberry Pi 3 which sounded like an easy thing to do. Yet, downloads seem only interested in Intel processors so how is Calibre loaded onto a Raspberry Pi 4? Keep in mind I’m a financial guy not a computer person. And does one lose functionality going this route? Would I be better off just purchasing an Apple Mac mini and accessing with my iPad via Luna?

Many thanks in advance!