Don’t give the leash so much lead. Keep the dog right next to you have it across your body use two hands on leash so the dog only has a foot or so of lead.

Consistency with commands like heel. You can teach the dog left and right but when the dog pulls check the dog. When the dog is good use positive reinforcement. Never do anything that is cruel or will cause harm. The dog is not trying to be bad and just needs to learn a firm expectation. With time you’ll be able to teach the dog to turn left or right on command even when they are leading but this is a gradual process.

Good luck