1. What do you LOVE?
Love trumps everything else. I love writing, and I enjoy teaching. However, neither of these areas pays particularly well. My enjoyment more than makes up for it however. Sometimes a specialty will choose you. You specialize in an area because you spend a lot of time thinking, reading and writing about the area.
What do you spend all your time talking, thinking and reading about? It may turn out to be a specialty, once you start writing about the area.
You can specialize in odd things: things most people wouldn’t dream of. One of my students was a real fan of gossip and celebrity websites. She joined forums to catch up on the latest gossip. A forum owner asked her to become a moderator, and she did. This led to her writing a regular column for a website. Then she was asked to assess manuscripts for a literary agent. When I last contacted her, she was still moderating, and writing regularly for a large website. She managed to turn gossip into a career. Who knew?