how do a save a website to a folder

If you want to save the page to be read off-line, from the file menu select Export and choose Web Archive. This selects a single page, not the entire site. If you want to save the URL to double click later, click and hold the little icon in front of the URL and drag it to a folder or desktop.

Copy and paste works the same on a Mac as Windows except the keyboard shortcut key is Command (next to the space bar) rather than Control. Many of the keyboard shortcuts you know on Windows work on the Mac by substituting Command for Control.

Do you mean add a shortcut to the site?

Drag the icon on the left inside the address bar into the folder.

Do you mean copy & paste shortcuts?

Shortcuts in OS X are pretty much the same as Windows but replace CTRL with Command

Copy - Command+C

Paste - Command+V

Undo - Command+Z

Select All - Commad+A

etc...

You can run most applications in either Fullscreen mode or normal mode. Unlike Windows, for most Mac users, normal isn't fullscreen. If you are in fullscreen mode, at least temporarily, move out of it by move your cursor to the top of the screen and holding it until the menubar appears. Then click on the blue arrows in the top right corner. Now resize your Safari window so it doesn't take up all the display. Now switch to the Finder and open a folder window. Resize it and move it so some of the window will be seen when you return to Safari. I've done a screen capture to demonstrate.

Now you can conveniently drag the URL to the folder below.

Do you have Safari fullscreen?

If so, hit escape on the keyboard. Otherwise, just drag the window to make it smaller