There's no "i" in macOS—at least, not anymore. Apple replaced "iPhoto" with the more generic-sounding "Photos" back in 2015; then, in 2019, they removed iTunes, replacing it with separate apps for ...
To make a custom ringtone for an iPhone, you'll need to edit a song using iTunes on your computer. Here's how to do that and copy it to your iPhone.
If you've ever found yourself scrolling endlessly through your iPhone's music library to find that one album you play every morning or the workout playlist that gets you pumped, then you should find ...