How can I backup all of my files on a Mac?
If you want easy, connect a drive, set up Time Machine and forget about trying to micro manage settings. It just runs.

If you really need to invest in a selective backup, I would still recommend Time Machine and it will have a 120 second count down before it starts the first copy. Turn off Time Machine so you have time to go in and configure exclusions for Time Machine.


Exclude System files and applications. (I always exclude those - not sure why that’s not the default other than people might not have good internet to download an installer if they need one.)
Exclude /Library (since you want settings to not be backed up)
Exclude ~/Library and any other folders in the home folder you wish to exclude


If you want to be thorough, show hidden files and also exclude /private - these two tips will help you quickly navigate in the open / select dialog:


How to show hidden files on mac without Terminal
How to change path in Finder by entering the path manually?


This way you get all the benefits of Time Machine like snapshots, local backups, second-disk backups with rotations possible to multiple destinations (third disk or more destinations are supported) and you can carefully control exactly what folders get backed up.

Once your exclusions are set, don’t forget to turn on Time Machine and let it run for the first backup. But really, I recommend backing up everything and not worrying. You’ll save a little space and time once if you exclude System Files so that’s worth it if you decide to do other pruning.