The problem with your approach is when you create a new project with the project manager, it needs to be initialized. So when you create the first project, all the config files and database connections are set.
When you try and create the 2nd project, it runs into the database that is already configured and throws the error.
To solve this, clean out the directory of your 2nd project and copy everything from the 1st project folder into it. (this way the 2nd project is also 'initialized').