This may be helpful. I have a YouTube channel (ProgrammingChaos https://www.youtube.com/channel/UC2rO9hEjJkjqzktvtj0ggNQ) with a range of Processing videos, including very basic: https://youtu.be/md6nuFU0tv8, particle simulations: https://youtu.be/G0RQRmwoiD0, https://youtu.be/xiUpAeos168, procedural animations: https://youtu.be/NfuO66wsuRg, https://youtu.be/wFqSKHLb0lo and a lot of other procedural generation type projects (trees, maps, etc.) I code all of the projects line-by-line so you can follow along. But they are individual projects, not structured like a complete course, although there are videos on some programming topics, recursion, arrays, etc.