Renaming, building

I imported an Arduiono project (.ino File). Wondering why I don’t see the build/clean etc. pop up menu choice.

In the attached picture, why is under 1. the name “UNBENANNT (ARBEITSBEREICH)?”
How do I rename this to sth. meaningful?
And 2. How do I rename this to something else? I don’t like this automatically generated name.

This question is related to VS Code, not Platformio.

You can give your workspace a name by saving it:

I can see from your screenshot that you have several projects in the current workspace.
This is fine, but sometimes difficult to handle.
I therefore recommend using only one project per workspace.
This makes your life easier and you are always on the safe side.