Oh dear.
Using JOSM for your 1st edit is definitely not recommended.
Doing the same with iD (the editor embedded in the OSM website) is faster and there's even a tutorial that will explain a bit about how things work.
That's a fair point.
I mainly chose JOSM for this tutorial because of its filter. As a beginner (just a few weeks ago), I couldn't figure out how to use iD's filter to show JOSM's equivalent of `name=* ((amenity=* "addr:housenumber"=*) | shop=*) -website=* -"contact:website"=*`. For this tutorial I wanted something better than than "click around the map until you find a place without a website." That felt like it'd be a frustrating and inefficient first experience.
Is there a way to make that filter in iD?
Tried to run JOSM, it tells me that "This app cannot run on this machine you have macOS 10.14.6 and it requires 10.11".
Just use the web page. It works, it's not hard to use and it's immediate when you have the urge and motivation to fix something on a map.
Yeah, I got as far as "Search for an Official Website". Didn't know what the hell I was looking at or for, and uninstalled JOSM.