These lessons are free. Do NOT sign up for the paid lessons or give your credit card information (unless you want to pay for more lessons from Udacity). The introductory videos are available free of charge.
This lesson includes 36 very short videos, walking through the process of installing the Android Studio Development Platform and developing a basic app that displays a table of weather forecasts for the week. You will have about two hours in lab/discussion section spread over the next two weeks to work on this. This should be enough time to complete the android development environment installation and the app, but if you need more time, you will need to do this on your own time.