This is probably going to feel obvious but YouTube. You can learn most of the things on YouTube nowadays, there are videos and tutorials for basically all hobbies.
That's my first go-to place when I'm learning something new, and then I try to understand who can be good people to learn from and follow them on other media as well (mainly twitter).
I think YouTube maybe helpful for someone who has decided what to learn but not for someone who's looking to explore learning random things without spending more than few hours.
Youtube is awesome for that kind of stuff. You can learn almost anything (that doesn't offend the censors).