Assuming you are on a desktop or laptop computer, hit the "Desktop" tile and proceed to use Windows 8 exactly the same way you always used Windows 7. For all practical purposes, on a desktop the "tile" menu just replaces the start menu.
Yes, except that with the old "Start" menu, because it was hierarchical and because each item was much smaller, you could pack a lot more information into it than you can with a screen of tiles.
As things are unfolding, it seems we'll have both a tile display and a hierarchical tree behind the old "Start" button or some equivalent.