I want to rephrase this question for you (and perhaps take it a little too far to be quora-esche" by asking you What do you enjoy learning. Arguably, you already have a pretty good answer - you’ve done training with GPUs, and if you’ve continued it you must be having fun! So the answer to your question is simple - first become a participant in Software Carpentry, and give yourself the broadest exposure possible to the different topics. You will find yourself in one of two situations:
- you have vision for how your ideas fit into something that exists
- it doesn’t really fit.
For the first case, you can then identify the teachers and points of contact to discuss how you can fold in. For the second, this is the more fun opportunity, because you can reach out to the organizers and propose a different idea. You don’t even necessarily need to follow some preset template of “a teaching session must have slides followed by hands on programming” - you could arguably teach in a way that best brings out your passion and has worked in the past.
Likely both of the above will lead to good conversation, development, and be more productive than signing your name on some sheet and trying to fit the teacher mold. If the students are to best learn the material, they will do so from the teachers that are most excited to teach it. The teachers that are most excited to teach it probably are having the most fun doing it. That’s how I would go about getting involved, and +1 points for making your material version controlled, possibly reproducible for others to teach, and thus having an even larger impact.