Don’t eat for 30 minutes before you exercise to avoid cramps.
If you know that the muscles biceps, rhomboids, latissimus dorsi, and posterior deltoids all contract and shorten to move the shoulder and arm, you will understand the exact benefit you get from doing a lateral pull-down.
If you don’t go to a gym, watch video tutorials and work out in front of a mirror or film yourself lifting weights to check your form. Pay special attention to any aches or pains you feel while lifting.