I always find instructions worth a read. That way I know how domething should be operated. My wife has a different approach – she presses buttons, throws levers, and bangs things until they work the way she wants them to! 
I have no idea what you did to break things, other than moving some project folders around.
I’m sure that you uninstalled VSCode, and by doing so, the PlatformIO extension. You also removed the PlatformIO tools etc from your user’s account.
In other words, you have cleaned up, ready to install, so it should be a simple case of installing VS\code, adding the PlatformIO extension, opening an existing project, and compiling.
It’s not working! So, go to Help->Toggle Developer Tools, then click on Console – is there anything listed in amber/yellow or red? If so, please copy and paste it here. Thanks.
I don’t know what “0 kits” means as an error message - the required toolset/compilers/etc should get downloaded on first compile.
You don’t happen to have installed Python 3.9 have you? Can you run python --version in a command line session. 3.9 has, I believe, broken some PlatformIO installations. I’m not sure why.
You might like to check if PlatformIO is using your installed Python or its own version. Go to settings in VSCode and search for “platformio python”. Is th option to “attempt to use a portable python interpretor” checked or unchecked?
Whathappens if you toggle it and try a build? Anything? Reset it back afterwards if no joy.
Cheers,
Norm.