That’s a very good question, and I assure you that I’ve been meditating a lot about this during the last few weeks… For example, I already joined the Execution Environments workgroup here on the forum, where we identified a problem with it’s documentation across different places:
I thought of doing my first collaboration on the EE’s documentation area, since I’ve an special interest on this. I’ve never collaborated on any Open Source project though, so I’m still trying to get used to the mechanics (that’s why I spend most of the time collaborating on the forum’s get-help section).
Also, I’ve identified an ansible-navigator feature that I believe it would be great to have:
Not sure if that’s even possible… but what the heck, If I don’t try I’ll never know 
So to start with, I’d start collaborating on those two areas: Documentation & Dev-Tools features / bugfixes, since it’s what relates the best with my current role at my workplace. Anyway, I wouldn’t mind to get away from my comfort zone and become involved in community matters also, since I’m here not only to become more skilled on Ansible stuff, but also to build new frienships 