When you start Photoshop, the Tools panel appears at the left of the screen. Some tools in the Tools panel have options that appear in the context-sensitive options bar.
You can expand some tools to show hidden tools beneath them. A small triangle at the lower right of the tool icon signals the presence of hidden tools.
You can view information about any tool by positioning the pointer over it. The name of the tool appears in a tool tip below the pointer.
If you're looking for general information on how to use tools in Photoshop, see Using tools.