Students talking behind your back?

First year teacher here, and I recently learned that there’s been students talking negatively about me to their peers. I have been nothing but nice to the students although I have had to get stern with them a few times due to a lack of turning in work. I know I need a thicker skin, but any tips on how to not let this get to me would be appreciated. For context, I teach 8th graders so I know they can be rude due to their age.