If the tool bar is black (or dark gray if you prefer), you are in Privacy Mode. There are two ways to toggle this mode, both fairly easy.
One is to start a new tab using the + icon. You will see the Privacy button at the bottom left of any empty tab.
The second is to tap the URL field and go into edit mode. This will bring up the keyboard. The Privacy button will be just above the keyboard on the left side of the screen.