I recommend macmost.com as an excellent resource for short Mac video tutorials. Here’s one on customizing toolbars. https://macmost.com/customize-the-toolbar-in-the-finder-and-apps.html

Another thing: if you have a frequently-used app or two, you can drag those to the toolbar at the top of a Finder window. They will then be available from any open Finder window. At least, it used to be that way. It my be necessary to hold down the option key while dragging now, I can’t quite recall.

On the subject of macmost, the website publishes a printable PDF of the most common keyboard shortcuts.

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