Ella, if you go to the main menu, then click on options, you should see "Pause Game" with "Yes" and "No" boxes. Click Yes to make the orange box appear there and your game will be paused (Click no to Un-Pause the game)

There's also another way to pause (and un-pause) VF and that's to press the spacebar (Once to pause, once more to un-pause) I hope this helps!