I'm shocked how unusable this is. Configuration is not simple and not documented. Appearance is primitive at best, not even basic. But in the end it's totally worthless as all the basic access functionality is missing or does not work. No registration page/ link on login page. No documentation on setting this up. blogs all point to manually making a registration page using shortcodes?? But the codes don't work, so the plugin is just useless. From here I tried Asgaros and while simple, it actually works in full out of the box with easy configuration all in one place (not 3 like bbpress). Sure if you want a nice registration form you need another plugin, but that was already the case for Wordpress anyway.
We wanted to try BBPress but we discovered quickly that it caused way too many problems with roles & permissions for the site. So we removed it. But it turns out that for at least 8 years bbPress has known the roles can't be removed cleanly and they just shrug and say "not important." So, I recommend you NOT INSTALL THIS PLUGIN. It will leave ugly traces behind itself like a nasty WordPress slug and you'll waste hours googling it and trying to fix it to no avail. It's old, it's ugly, and it's a mess.
If you've ever used other forums software, or especially if you've deployed other forums software, it becomes very clear after you install bbpress that this plugin is basic, and clunky. An awful lot of what would be considered standard functionality in forums software simply isn't present, or if it is, is awkward and clunky to use.
Having said that, it is the best forums plugin I am aware of for WordPress, perhaps the only one, and it is FOSS, so hurrah for that, and it mostly does the job. There are also plugins available for it that extend it's functionality and add features which almost put it on a par with other forums software, but even with those, not quite.