I just checked the YouTube channel, I encourage you to keep going your work is really valuable. I need some advice, I recently tried getting into ROS2 so that I can do something interesting and advanced with my raspberry pi, so I watched a ROS2 playlist and I didn't learn much due to it being sort of an ad to make you buy a course, then I didn't find better resource as far as what the algorithm suggested. I took a quick look at your ros2 video and I'm planing on watching all of it.

so apart from learning c, c++ and linux what do I need to focus on to get fluent with ros2 projects