Visual Studio does not open up with the good solution

I just installed Unity, made a test project, created a script file and double-clicked it and I see that a Solution1 solution is opened but I don’t know how to, for example, use another assembly.


Please advice.

In the context menu of a script I click Open C# Project and the window that pops up is from File Explorer with the project directory, not the Visual Studio window with the project open.

Solved. I just had to go into Edit > Preferences > External Tools and set External Script Editor to Visual Studio Community 2019, then click on Regenerate project files.