Originally Answered: Is this a good 3 paragraph essay? Please help me improve it?
It doesn't suck at all- you have done a great job. Please understand that my corrections and suggestions to you are in the interest of making it the best it can be, not to criticize or try to make you feel that you haven't done well. I think you could easily submit it as it already is and have a fairly positive response. Here are my suggestions:
FIRST PARAGRAPH: first sentence, change "apposed" to "opposed". second sentence, I would suggest changing "thing" with "program" or other more specific word ("thing" is so vague, it's often frowned upon). last sentence, capitalize "I" throughout the sentence. Maybe instead of saying you lack confidence, it would be good to just focus on how the experience would help you gain more conficence; example: "I think that the healthy competition I would experience in your school would also help me gain more confidence in my academic pursuits." (just an example, but you can use it if you want)
SECOND PARAGRAPH: maybe replace "picky" with something that doesn't have the negative connotation, like "diligent", and I would suggest just saying that you are also very 'grammar conscious' or something like that, instead of talking about annoying your friends :-) the next sentence, as far as technical stuff, is a run on sentence- you can either exchange the comma for a semicolon or period, or add a conjunction, like "and". Toward the end of the paragraph, I would consider replacing "shoved in my face" with something a bit less casual, like maybe "forced on me" or "pushed on me" or even "imposed on me". Also, "sister's" is a possessive- if you mean more than one sister (as opposed to something that belongs to your sister), leave out the apostrophe. Capitalize "I"'s throughout these paragraphs.
THIRD PARAGRAPH: The first sentence is a run-on. Consider replacing the comma with a period and making it into two sentences. I would also consider changing that whole statement to something more positive sounding; example: "I have always been interested in music and have played around with learning an instrument, though I have not found one that I care to pursue long-term." The sentence beginning with "Music has always..."; you have it ended in a preposition, which is a no-no, and it's a little awkward with the wording. My best suggestion for it would be, "Music has always been an escape for me, and can usually improve my mood and help me gain a positive outlook on difficult circumstances." The last suggestion I have for this paragraph is in the last sentence, rather than stating something negative about your lack of interest in sports, I would think of making the whole sentence more positive, focusing on what your interests are. Like this: "I am an arts oriented person, and have always been more interested in activities such as photo editing and drawing rather than sports."
Again, you have done a good job- these are just suggestions since you requested help in improving your essay. I hope I have helped. good luck to you!