Congratulations!
First of all, you've got to tune out your friends and the entire wedding industry as far as "you need this and that and Pluto" to get married. You actually just need the legalities and that's it.
I strongly caution you on throwing a potluck, unless your wedding is very small. I advise you (I know, here I am throwing advice around
) to let your guests be guests and don't make them "work". There are ways to provide food and refreshment that doesn't break the bank, even if it's cake and punch. That used to be the norm, anyway.
There may be legalities around throwing a potluck and using the hall's kitchen, also. Take it from me speaking from experience, the aggravation and extra work on you isn't worth it. I learned it's far worth the money to hand it over to caterers, including set up and serving.
You don't need tuxes or wedding dresses. Since you have over a year, check out prom and homecoming season dresses coming out.
Above all, get organized and stay that way. And have fun
.