Janie, In Safari's File menu (across the top of the Mac screen, select New Window (Cmd N) and you should get a second (3rd, 4th...) window opening on whatever your home page is set at; I've currently got four open and earlier today I had about eight. They'll all be listed under Window in the same menu bar and clicking on any one will bring it to the front. Putting the cursor on the little square in the bottom right hand corner of any window on the Mac allows you to resize that window with a click&drag.

This all works on a one-button Mac mouse; the right click is only "useful" for Windoze applications.

I hope this helps.

Cheers, Rowan