"Will I look dumb trying this if I have never done so before?" goes the question that echoed in my mind
I suppose this affects everybody to some extent, (insert comma) but my revelation made me realize that I was not living life to its fullest extent.
You repeat "extent" twice in this sentence - I would recommend dropping the second one since it's both redundant and unnecessary.
This revelation changed my outlook on life. This all came about one very special day: December 27, 2010.
Might be just me, but one of my pet peeves is when two adjacent sentences start with the same word without serving an obvious purpose. You could combine the two sentences to avoid the redundancy or somehow change them so they don't start quite so similarly.
Cheeks red from the cold and smiling from ear to ear, I was skatingskated
Not looking embarrassed nor sheepish at all, I found her grinning up at me.
Your friend's the subject of the first part of the sentence, so the second part of the sentence should reflect that. Change it to something like "she grinned up at me." Also, I'm not entirely sure about this, but is "or" more appropriate for this sentence?
I made mistakes, I fell a lot, I got my clothes dirty, but I was enjoying life way too much to worry about these petty details
This sentence should demonstrate parallelism. You made mistakes, you fell, you got your clothes dirty. The part of enjoying your life should be similar grammatically, so replace "I was enjoying life" with "I enjoyed life"
It had gotten locked away inside me because of the stress of wanting to meet the high expectations of everyone around me; my family, my peers, my teachers.
This is unnecessarily wordy. Also, replace the semicolon with a colon - you use semicolons when you're putting two related sentences together and colons when you're listing stuff.
My friend gave me the encouragement to stay true to myself, to make mistakes and not be scared of the outcome.
Same - parallelism. Replace "and not be scared" with "and to not be scared"
because I realize, that by trying new things, I could be so much more.
or you could just reword that
because they can tell me a lot about myself and I can improve based on these mistakes.
kind of awkward
Hope that helps!