Let's start by looking at the MATLAB interface.

There are a few important components that you need to know:

You can enter commands at the command prompt (>>) by typing in a command and pressing Enter. Commands entered this way are executed immediately (later we will look at saving code as scripts which can be run at a different time).
If the command you entered produces output, MATLAB will print this output on the next line.
If the prompt is unavailable, it usually means MATLAB is busy. The status message (4) will indicate MATLAB's current status.
You can use the up arrow to look at previous commands.
If for some reason your code is stuck or has been running a long time, you can select the Command Window and press CTRL + C.

Variables that are available to MATLAB will be displayed in the Workspace.
Double-clicking a variable will open a new window allowing you to explore its contents. Be careful doing this with large variables as it may cause MATLAB to freeze or crash.

Indicates the current working directory. This directory is important as MATLAB searches for files and functions in the current directory first.
The information for the working directory is displayed in two different places:
1. The path (i.e. location on your computer) is displayed in the navigation bar above the Command Window.
2. The contents of the folder is listed in the Current Folder panel
Your path might look different than the screenshot if you are using Linux or Mac (all screenshots here were taken using version R2020a on Windows 10).

If MATLAB is not doing anything, the message will be blank and the command prompt >> will be visible in the Command Window.
If the command prompt is not present, the message here will indicate what MATLAB is waiting on.