A particular concern of mine is whether the purpose of the club is clear to those who aren't familiar with it.
No, you need to briefly describe the organization and its aims for those who are unfamiliar with it.
I worked with the founders and had initiatives and new ideas, some of which were implemented.
"Initiatives and new ideas" is simultaneously redundant and vague. You need to be more specific.
How can you do that within your word limit? By editing out superfluous words, phrases, and sentences to make room for more vital material. For example:
I
applied for and received the position ofbecame Business Director/President and immediately started planning the annual charity fashion show,
the club's most significant event .
Even though there was a Creative Director in charge of the more artistic logistics of the show, I helped put together outfits and create a show line-up. I also compiled
a list of songs for the show
music and helped edit the DVD
recording of the show.