Welcome to HubPages. You pretty much write about anything that you like. In the BL&W topic, my Hubs are on writing - character development (coming soon), writers' block, and inspiration. I also post Hubs to other topics (from time to time) on Australian politics & patriotism, and transgender issues.
Some Hubbers cover an even more diverse range of topics than that.
The best advice I can offer is to write what you know and care about. Good luck, and I will check in and see how you are going.