I always feel pain on the left and right sides of my neck during dumbbell exercise.
This is normal. When practicing arm muscles, it is easy to drive the muscles on both sides of the neck (trapezius muscle). In fact, lifting, pulling and lifting in our daily life are inseparable from the trapezius muscle, so we should pay attention to the movements when exercising. I don't know what you are doing, so I can't say anything, but it doesn't matter even if you practice. Ask me if you don't understand. I have been working out for 2 years and have rich experience.