Hey @drnooe!
In the YouTube video you linked, we don’t actually see VS launching as the project gets created, it’s just a cut. The VS would launch however when you create a new C++ class inside the editor from the Tools menu.
Now when you wanna open your existing C++ project, the standard is to build it from VS, which you can do by first opening the .sln file from File Explorer, VS, or any third party software where you can open the .sln file such as P4V. But you don’t wanna launch the editor from Epic Store or File Explorer by opening the .uproject file. If you do everything will probably be fine but it’s just an inconvenience in the development process plus it can cause issues (while not being irreversible in most cases), so I say make it a habit.
After opening the .sln file, to build the project, simply hit Ctrl + F5 inside VS, or hit F5 to build and start the debugger.
Hope this helps! 