A few general comments:
You know those people who get excited when they can fulfill mundane tasks and simultaneously save the planet?I don't like the use of the phrase "mundane tasks." Is art a mundane task to you? Something more appropriate would be enjoyable activity or personal interest.
NAHS epitomizes the prototypical school clubA prototype is defined as "the original or model on which something is based or formed." I think a plain "typical" fits much better.
I seized its opportunity to interface my interest in art with my desire to make things happen.Use "this" instead of "its."
I assumed leadership of NAHS' most logistically ambitious project yet, a trip to Chicago.Use a semicolon instead of a comma.
The thrill of proving myself and bettering the experiences of others inspires me."Bettering the experiences of others" is somewhat awkwardly worded.
Overall the information itself is very impressive, and I like the last line, which ties it into something practical.
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Now on shortening it down.
This is an extremely short essay, so get straight to the point -- a cutesy introductory sentence isn't really necessary. You can probably cut out the first two sentences and simply say, "The National Art Honor Society (NAHS) epitomizes the typical school club: every activity is truly the result of student initiative." Or, even better, "The National Art Honor Society (NAHS) gave me the unique opportunity to combine my interest in art with my desire to make things happen." and edit from there.
Caley Shem-C.