Male buissness casual dress code for school event?

I'm being inducted into beta honors on fairly short notice, and I'm very poor and can't afford new clothes by then. I have a fairly nice small print black and white checked shirt (so small it looks grey), a black belt, slightly baggy grey khaki pants, and either women's ankle height black leather dress boots with a small heel (that are slightly beat up) or more functional men's boots with fleece lining and tan suede material. As far as jackets go, I can borrow a slightly small faux leather jacket from my sister or wear a non-dressy coat. Is this appropriate and which shoe and which jacket would make the better option? Also, for jewelry, I do not have a watch but I do have two earlobe pericings and either might borrow some zircon studs from my sister or wear some small/meidum sterling hoops of my own. My parents don't really understand the dress code.