“Well, I wasn’t always this abnormally covered with hair.” Just add a comma after “well”.

“If you haven’t already experienced puberty take my advice: it is not nice.” For this sentence I’ve replaced the ellipsis with a colon. It’s somewhat optional but it makes it easier to read.

“All the signs of turning into a woman and I had many questions.” I think it would make more sense if you wrote “With all the signs of turning into a woman, I had many questions.” This is also optional, but I thought I’d make that suggestion to make it more understandable.

“……The reason I picked puberty was so I could inform my classmates’ answers to questions that would otherwise be too awkward to ask.” Just put an apostrophe after “classmates”, and you’re good to go. You want to make sure you add an apostrophe because it’s a plural-possessive.

“I, on the other hand, think kids should be well-informed; otherwise they will be scared and unaware of what’s happening.” This needed commas and a semicolon to avoid turning into a run-on sentence.

That’s all I could find.
This is very good, BTW.
Good luck!

Pretty awesome, especially the Norris reference!