Very good idea to learn technology. Good luck.
Last year Shekhar did "52 technologies in 52 weeks" and he shared all the details here: github.com/shekhargulati/52-technologies-in-2016. You may get some ideas from there.
I keep an idea-swipe file. Some ideas from there:
I go for public speaking often. I look for related short stories or quotes. If there is a db which I can organize with tags, then I can quickly search depending on the event and pick up. If it is searchable via mobile, even better (doesn't have to mobile app, just accessible from mobile)
Scan twitter for #isthereanapp or #killerfeature and help me store them into a local db with tags. Whenever I get a time, I will choose from that list to implement (it can help you too)
Given a linkedin group, list out the members and their designations
Good luck. Will be keen to follow.