I'm scared I accidentally submitted the wrong file and was just wondering if I withdrew my submission would I be able to send it back in? Also there was a question asking about what stem organization I'm in, it said it was optional but it forced me to choose one so I chose other and typed "None of them", that should be okay right?
What happens if you withdraw? Are you able to submit again?
Yes, I think you are able to submit again.
For the second question, I don't think it's a problem. Check this thread.
No that not a problem you can withdraw and send again