This article explains how to find out how much available storage space you have on your MacBook's hard drive. The information in this article applies to MacBooks running macOS 10.15 (Catalina) and later.
To check the available storage space on your MacBook using your hard drive icon, follow these steps:
Right-click (or Control-click) the hard drive icon on your MacBook desktop.
In the pop-up window, the Available line will indicate how much storage space your MacBook has.