From the welcome screen, you can open a folder on your computer by clicking the Open... link

Usually you don’t have this “welcome” screen enabled, and you use the menu File -> Open folder....

One thing I generally do is: drag a folder I use for my project into VS Code itself, dragging the folder icon into the VS Code window.

This opens the folder in a new window, for example here I opened an empty testing folder:

If that folder contained files, you’d see them in the Explorer sidebar. See? The little icon in the Activity bar is now highlighted, it means you’re in the file explorer.

Lessons in this unit: