I have a story that I really want to write, it's about two girls who are friends. One lives with her abusive father and lights fires to cope with the stress. The other is waking up to the fact that her friend lights fires and wants to help her. I just don't know which girl I want to present as the protagonist, or the one telling the story. What do you think would be more interesting?
Personally, I'd like to explore the mind of an abused pyromaniac, but you could can go either way, so long as you feel confident you can portray the character in the most interesting and believable manner. Also, welcome to the forums!
Why can't you do both? I had a similar problem with two of my charries but then I decided just to write it in third person and see whose head I naturally fell into. If you're writing in third person there is really nothing stopping you writing both of them as major characters. If your story requires the first person POV then you could always switch between them chapter by chapter or whatever works for your story. If you really want to have only one as the protagonist you need to decide what your story is really about. Is is about the girl struggling to live with her father and lighting fires, in which case write as the pyromaniac, or is it about how her friend copes with this and tries to help her, in which case you might prefer to write as the friend. It is your story, only you know what the essence of the story is and hence only you can make this decision.
I agree with EllBeEss - both can work well. If you are using first person, then you don't have to switch between the two characters every other chapter; just make it clear whose head you're in. Same with third person, really. If you only want to have one POV, write a sizeable scene twice. In one, use the first character, and then write the scene with the POV of the second character. From there, you should be able to see what works best for you (and your audience - give both scenes to readers and see which one they prefer, too).
As others have indicated, you could tell the story from both points of view, but you have to be careful about making it very clear whose POV you're in at any given time. Too much "head hopping" can be jarring and/or confusing to the reader. Even if you're using third person POV, it can be a useful device to switch POVs in different chapters. (It doesn't always have to be done this way, but it can make things easier.) However, it is also possible that the story might be better told just through one character's POV, leaving some questions unanswered and allowing us to discover things along with the MC. I would suggest writing a bunch of scenes from each character's POV, and see which one resonates more with you. Even if you don't use half of what you write (that is, from the character whose POV you don't use), it will still be helpful for you in terms of getting to know that character and therefore being able to write her better.
Just from your description you seem to be more invested in the pyro girl. Write what YOU want to write about. If you're not interested in her friend's story then go with pyro girl :3
I like being the outsider looking in than being the one doing the insider things. I wanna use my imagination to guess what is the pyromaniac's problem. I don't want to know right off the bat, it'd take away from the character's mystery imo
First off, the narrator ("one telling the story") is not necessarily always the protagonist. You can make the girl with issues the protagonist but the other girl can be your narrator, she would be the camera, if you will, through which the readers will observe the protag. Apologies if I am repeating anything... I haven't read the other posts.
The girl with the abusive father would be an excellent choice. It seems like you can write her with a lot of emotion and depth.
I think it depends on how you want to approach the story; do you want the reader to know what exactly is going on from the beginning? Then you should write from the abused girl's point of view. If you want the reader to discover the abused girl's motives along the way you could write from the other point of view. If you think both perspectives can provide interesting information in different parts of the story you can switch. If you don't want to switch between points of view you can use the third-person subjective where you describe the thoughts and feelings of multiple characters. I would not pick a protagonist right away; try to start with writing a few chapers and see who has the most important role in those chapters, that character will become the protagonist. I don't know if that's the right way to do it, but it always works for me.
There is more mystique if we watch from the friends point of view. It allows you to blind side the reader with a fire or behavior act that comes from out of the blue. But if you want to focus on mental health and what the protag. feels then you can delve deeper with her point of view.