Web2Py is the glue between a database and the user interface - say a web site, HTML pages.
It doesn't have a database, so you'll need to use either SQLite (built in every Mac) or some other DB.
Personally I suggest using MySQL - it is open source, industrial strength and will help you grow out of MS Access into a real-world database.
When you'll have everything up and running on your local machine - you'll need to deploy to a hosting service so people can access your app over the web.
Creating a phone book like you have mentioned is really easy - both on the DB side and the Web2Py side.
I have managed to create one in several hours when I've started learning Web2Py.
I have tried other "glue" frameworks before W2P, such as Django, PHP and others.
W2P is by far the most friendly one I have tried and it will take you from 0 to a reasonable level in literally a couple of days.
Good luck and have fun