I would say join large groups on Facebook and see what people are most passionate about. That's real data there, within a few days you'll see the things people like to talk about and the posts which get the most engagement. Honestly, you can even ask the people in these groups what they're most interested in with regards to content.

Then when you create a list of these topics, search on google about these ideas and work on putting together a substantial amount of content. Create it and then ask these people in your group what they think. Facebook groups are powerful and they can be your own honest critics.