Learning a second language – Duolingo has figured out to gamify learning for even us ancient of days. Their algorithm seems to learn with me and helps me improve where I am week (conjugation) (free)
Formal education – if you are ready for a course audit or even an accreditation from a reputable college, there are a couple of Massive Open Online Courses (MOOCs) Udemy and Open Yale I have found interesting and accessible and (free).
Daily News – need your fix of curated daily news stories The Upshot and most other outlets will either confirm or challenge your biases.
Blog Posts – I have experimented with a couple of aggregaters but Feedly seems the most search friendly and easiest to glean and clean. Start with a couple of interest areas and see where it goes
I try to stay on top of my goals and HabitForge or other reminder sites seem to be just the right amount of push to get me to act and report but not so much that I rebel
For fun, engaging personal interest learning that is uncurated, non reviewed but has been a lot of fun, check out Blab.im I like The Craft Beer Blab and TravelChats but there is lots to choose from and you can create your own.