How do I delete a project in Xcode?

Use the Finder, not Xcode.

With Xcode closed, locate that project folder in the Finder, move it to the trash, then empty the trash.

I'm totally new to Apple, I can find Xcode in the finder but not individual projects. How do you do that?

Xcode does not choose those locations....you do.

When a new project is created, a dialog is presented and that location is chosen by you at that time.

What you can do is to note a project name in Xcode, then use Spotlight to search for it on your drive. Note that there will be multiple references, including not just the parent folders, but the derived data from any project that has been built.

Alternatively, in Xcode, using the Navigator (left pane), expand the group "Products", right-click on the .app file and choose "show in finder".

An optional, albeit a bit clumsy, method is to make a change to a given project and then use the Finder to locate files modified in that time span.

See Xcode Help for various details on it's use.

If you're not familiar with macOS, you may want to take a bit of time to learn how to use and navigate the Finder, desktop, etc.

If you have further dev-centric questions, you may want to start your own thread rather than continuen to tag someone else's that has already been closed. If you have questions surrounding macOS use, feel free to use Apple's public community support forums: https://support.apple.com/

Close xcode first then open it again , at rigght menu you will see name of your project , clikc on on 'show on finder' .Then delete the project folder