Others might know more but speaking additional languages isn’t that big a deal at the top schools. Many of the international kids speak several languages. It might be an interesting conversation point in an interview but probably won’t weigh heavily on the scales.
Concentrate on your grades. Prep for the ssat. Get to know your 8th grade teachers quickly next year so they can write great recs for you.
If you placed in those swimming competitions you should certainly explore swimming at these schools. Fill out athletic interest forms when you schedule your interviews next year. Schedule your interview/tour early. Do not wait till the rest of your application is done or anything like that.