In each project folder is a python file for a coffeeshop app. Follow the enhancement instructions in that folders PROJECT#.MD file. If you get stuck or need help you can cheat by looking at the next folders coffeeshop.py as that should be a finished version of your current folders.
Make sure to do your best to not cheat ahead unless you're at wits end. Remember there's lots of ways to do things. Make sure to take your time comparing your solution to PROJECT# to whats provided in PROJECT#+1 as that's often a great way to learn.