For example, I want to execute this command from this tutorial:
$ adb shell monkey -p your.package.name -v 500
How do I do it? Where do I enter the command? I've tried entering it into the terminal but it says that '$' is not recognized.
I also tried removing '$' but it then says that "'adb' is not recognized as an internal or external command, operable program or batch file."
$
isn't part of the command.
Use adb shell monkey -p your.package.name -v 500
adb is the command you ran on your terminal. For example:
adb devices
shows you the connected devices.
adb shell
Starts a remote shell in the target emulator/device instance.
See https://developer.android.com/studio/command-line/adb.html for more info about adb.