In order to get started quickly once the participants actually meet, you should start your development journey by following the guides below. Depending on your learning type, you may choose one or many of these guides; it is entirely up to you how you learn, but please remember that you'll be a burden on the group if you don't learn.
For a guided introduction, consider checking out the following:
Follow along until you have finished the "Functional Programming" section.
If you still want some sort of guide, but prefer to learn in a more free way, consider going through the following sites:
If you are a visual learner, you can take a look at the following videos. Please note that they are not enough for you to start working with other participants that have started with the other tutorials, so they should only serve as an intro.
If you don't have an active internet connection where you want to learn, consider downloading (and reading) the following PDF tutorials: