Do the reverse, give it a try and then buy it. Keyboard Maestro has a 30 day free trial. I have no interest in customers who can't get value out of Keyboard Maestro purchasing it.
Each time Keyboard Maestro either saves or pastes from a named clipboard it makes use of the System Clipboard so, whatever is copied or pasted from the named clipboard also becomes the item in the System Clipboard.
If you want whatever was in the System Clipboard before using your Macros to remain, you can do that by using the Action Delete Past Clipboard to in effect reset the Clipboard each time.
So, for the Copy Macro:
Macro 1, Hot Key 3 trigger Ctrl +Shift +1
Action Copy to Named Clipboard 5 "Copy 1"
Pause for a short time (to make sure Clipboard has changed)
Action Delete Past Clipboard 0 (which returns the Clipboard to what was in there before)
And for the Paste Macro:
Macro 1, Hot Key 3 trigger Ctrl 1
Action Paste from Named Clipboard "Copy 1"
Pause for a short time (to make sure Clipboard has changed)
Action Delete Past Clipboard 0 (which returns the Clipboard to what was in there before)