Actually, that's only true if you're using default everything. It's quite different on my machine, not only because I've remapped My Documents to a different drive but because I don't tend to save project files in My Documents.

The best way to get at your project file is to remember where you save your stuff, then go look there. If you don't know where your files are, how are you supposed to deploy the result? Or back up the project?

A handy shortcut, if you aren't sure where your project is, is to right-click the project in Solution Explorer and choose "Open Folder in File Explorer".

I'm really not certain what it means if "Exclude File From Project" isn't present. It makes me wonder if you clicked the right thing. "Open Folder in File Explorer" should be there. If it isn't, either you're still not clicking on the right thing, or your Visual Studio has a voodoo curse and you should reinstall everything.