Will a post on arXiv as a high school sophomore hurt my future academic life? I am a high school sophomore student who is very passionate about the subject of number theory and college level calculus. However, I am currently only in the high school class of precalculus/trig. The paper contains material beyond high school calculus, but am afraid that it would not be good enough for an actual arXiv paper.  Here are a few important facts to consider about my particular situation.


(The math side) The proof is basically a non-summation proof of an inequality between an integral and a constant. By "non-summation" I mean like, if you have a sum of infinite terms, you are not allowed to approximate using 1000000 terms or whatever. This implies more strategic methods, no use of any obvious approximation methods like trap rule, and most importantly, in my opinion,  why I feel it good enough.
I feel that this is not necessarily good enough for arXiv because I am not proving some general result, have 0 co-authors, and very limited assistance on the subject.
I currently have no people to endorse, but quite confident I can achieve one (connections).
If this is too low level, I am afraid that this might mar writing papers in the future, my credibility, etc.
I have an unused arXiv account, which I doubt will be harmful (side question: will it?)


But, Ok, let's assume that I manage to pull this off during the summer. Assuming the paper is written fair enough, but about the content I am talking about, would writing the paper hurt my academic life down the road?
I suggest looking into publications that specifically target high school or undergraduate students. An example, but one that unfortunately no longer exists, is The Mathematics Student Journal (sample issue from 1971). A current one is Pi Mu Epsilon Journal. An organization that I've been involved with both as a student (mid 1970s) and as a teacher (late 1990s) is Mu Alpha Theta. These are USA based, but your teacher should know some appropriate for you.