Copy, Paste, Cut, Select-All Keyboard Shortcuts
Almost all of the keyboard shortcuts you've learned on Windows are the same on the Mac. The difference is which modifier key you use to invoke them.

On Windows, shortcuts are typically invoked with the Ctrl modifier key.

On the Mac, you use the  key, also known as the "command" key. It's in the same physical position as the Alt key on a Windows keyboard, but is nothing like the Alt key.

The Mac has its own Alt key, labeled Opt/Alt. Its primary use is a secondary modifier for keystrokes. Command-Option-S might be "Save As", for example, while Command-S is regular "Save".

The Ctrl key is there on a Mac keyboard, too, but it's hardly ever used for anything.


The relative layouts look something like this:

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;PC: &nbsp;&nbsp;&nbsp;&nbsp;Ctrl Windows Alt

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Mac: &nbsp; Ctrl Opt/Alt 


The problem is that you're most likely using a PC keyboard on your Mac. In that specific case, the Opt/Alt and  keys are reversed. You can change this in System Preferences, under Keyboard. Truly a huge pain in the rear for switchers. That layout looks like this, instead:

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;PC keyboard on Mac: &nbsp; Ctrl  Opt/Alt 


Apple's website has some pretty good hints and tips for Windows switchers. Start here for answers to your specific question about keyboard shortcuts. Then go here and read everything!