Hi,
Sure, press command+n (the command key is the one with the apple symbol on it) or go to the File menu at the top of the screen and select 'New Window'
If you want to use tabs, go into Safaris preferences and activate tabbed browsing to allow the viewing of several sites within one window. command+t will then create a new tab in the current window once it's activated.
Edit: ChristopherJim beat me to the punch 😉