I’ve done some professional mastering in the past, but would still consider myself very much an amateur/work in progress. I get a little better at it every year for sure.
But I will say, on ableton in the effect rack (don’t remember exactly where) there is/was a preset chain called “stereo enhanced master” which was really quite good. It was simple and honestly a great learning tool/starting point.
Another great way to learn is to load up presets on Ozone and kind of tweak from there.