Polishing/buffing scratches.

The scratch spans almost the whole drivers side, the scratch was there when I purchased the vehicle, I messaged the previous owner and asked if he ever did any type of paint correction (polish etc) and got no response from him. I know that if your able to feel the scratch it is through the clear coat I have Mr Sam’s light and final polish as well as a da polisher wax the whole 9 yards, if i polished the car would it cause more harm then it would help? I don’t need it perfect I would just like the scratch to be as least noticeable as possible. I’ve never polished a car but I will be practicing on a few cars before hand. Any advice is welcome thank you!