MacOS

Cut - Command-X

Copy - Command-C

Paste - Command-V

Select All - Command-A

Undo - Command-Z

You can then press Shift-Command-Z to Redo, reversing the undo command

New Folder - Shift-Command-N

Open - Command-O

Open the selected item, or open a dialog to select a file to open

Save - Command-S

Find - Command-F

Find again - Command-G

Find the next occurrence of the item previously found. To find the previous occurrence, press Shift-Command-G

New Tab - Command-T

Close window - Command-W

Hide the windows of the front app - Command-H

To view the front app but hide all other apps, press Option-Command-H

Minimize - Command-M 

To minimize all windows of the front app, press Option-Command-M

Full Screen - Control-Command-F

Print - Command-P

Force quit - Option-Command-Esc