[@TRES] I would start by introducing my character in a scene related to the setting; describe the scenery, have him/her experience something or perhaps interact with someone. I would base that experience or interaction on one of the themes of the setting and develop my character by showing him/her react to or comment on it. Then, I'd pick one of the openings from the articles in the OP and describe how my character intends to engage with it.

As stated in the OP, you can tag me in the post if you feel that your character is doing something in it that forwards the plot, or needs a referee to judge the outcome. Otherwise, you're free to just start your story.

I hope that helps!