For example, select the Zoom tool by pressing the Z key or the Marquee tool by pressing the M key. Click and hold down the mouse button on a tool that has additional hidden tools. Then drag to the desired tool and release the mouse button. Hold down Alt and click the tool in the toolbox. Each click selects the next hidden tool in sequence.
Most tools have options that are displayed in the tool options bar.
The options bar is context sensitive and changes as different tools are selected. You can move the options bar anywhere in the work area. In Photoshop, you can dock it at the top or bottom of the screen. Double-click a tool in the toolbox. All Tools from the context menu.