How to deal with immature people at work.?

I just moved to arkansas from living in california my entire life, i have had pretty good jobs most of my life but when i moved out here to a small town where my fiance lives there isnt anything hiring, so i got a job at mcdonalds out of desperation.Im very social and freindly and always have made friends with my co workers,but the people that work at mcdonalds are extremely mean,today i heard one of managers and a coworker talking bad about me and it bothered me, any tips on how to deal with this?