after installing x-code, how do I run the simulator?

I finished step 2 of this, but I do not understand step 3. Is this done in the terminal? what do I type exactly?

In a Terminal window, in the root of your project, type expo start

Then after it has started up, press the ā€˜iā€™ key in the Terminal. Otherwise press the " Run on iOS simulator" button in the browser interface that displays by default when you run expo start.