I was pulled over on the 15th of may, I pulled over, shut my car off and took my belt off to get my wallet from my back pocket. The cop was not actually pulling me over for my seatbelt. he thought I was on my cell phone which I wasnt and I can prove it with my cell phone bill I did not make any calls around the time he pulled me over. so he gave me a 240$ ticket for not having my seat belt on. I am trying to become a cop, and dont want this on my record, especially if I didnt do anything wrong unless I am supposed to have it on even if my car is parked and off. Is this worth fighting and if so do I have a chance?

You don't have to have it on if the vehicle is pulled over at the side of the road. You don't need to worry about a seat belt ticket affecting you too negatively during the police application process. It's very minor in the grand scheme of things. Just make sure to disclose it and be honest.