Where you go from here…As others have said, your parents should intervene with the principal - although how you approach it is dependent on some of the details of how this all came about (whether you were even given any explanation on how the grade was calculated, what that explanation was, what the grade was based on, who assigned the grade, whether each sub had entered failing grades throughout the semester or whether the most recent sub decided on the grade at the last minute, whether other students also had this issue, etc., etc.). Your goal should be to get the grade changed to a C-. If you absolutely can not get the grade changed - and again you will likely need your parents to intervene for any chance of this - then, yes, you will need to report this grade to all UCs to which you applied.
I have no idea if you cheated or anything else. Did the sub give everyone an F? Or just you?
There has to be a reason and the reason needs to be discussed with someone who has the ability to do something about it. Do you have any documentation about your personal circumstances? You need to involve the GC, the principal, maybe even the superintendent’s office. But if you did something to deserve an F, you need to ensure you have all your ducks lined up.
Any thoughts for OP @hanna?
Again, it seems time for you to get your parents involved and escalate the matter.
Curious if any other student in the class also failed the class.
Hey yall so this is my first time on this website and for some reason can’t edit/add stuff to the post.(Also I didnt expect to get this much attention 
) it dosent matter anyway since I got some answers. I did end up messaging my counselor- they said not to worry and they will come up with something. As for my parents (I only have one) said she’ll try to come to the school but its hard. She can’t miss anymore days of work. We don’t earn much. Which is one of the reasons why I graduated early, to pay for college. I might delete this later once I figure out how. Thanks for the sugestions I will report to the UCs later. I don’t want trouble, I’ll find a way talk or make up that grade. Once again thanks for the ideas.
If that F grade sticks, then you were in the top 2%.
I had this happen to a friend in HS. He failed English after getting into UCB. His fault for ditching school and not made up any work. Lots of begging and pleading and finally 6 of his teachers convinced the English teacher to pass him with a C grade so he can move on with his life.
Embarrassing🎶
Happened to me. It was a “teacher’s aid” elective as a senior. I did all the work (more than enough believe me. Gave me an “F” because he got mad at me for something. I was a straight A student. Went to front office with my parents and the lady in the office (who knew I was a good student) just declared it a mistake and changed it to an “A”.
Please be very clear on the reason you got this F grade when you go in to discuss this.
Closed at the OP’s request.