Toolbar

The floating bar at the top of the viewport picks what your mouse cursor does: select layers, rotate them, move the anchor, pan the view, or make a shape. Under the Move icon: Move V, Rotate W, Anchor Point Y, Hand H. Under the Shape icon: Rectangle, Ellipse, Polygon, and Star. Click the shape icon to drop the last shape you used at default size, or Shift-click to create it filling the comp. Or with the shape tool being active click anywhere in the viewport to create a shape at that position.

Drag the toolbar by an empty area to reposition it — it snaps to window and panel edges.