For most Android phones, the Menu button will be in the action bar:

For some devices, the Menu button is a physical button on your phone. It isn't part of the screen. The icon for the Menu button might vary on different phones. Here are a few examples of what the Menu button can look like:

Other devices might have the Menu button on the screen and look like this:

For phones without a Menu button, you must tap and hold the app switch button: