Hey, Steven.
I will share what I have done with my dog and hope it gives you some ideas. She was a 6-7 month-old-stray when I took her, and she had no idea what the leash or collar were, so I had to start from the beginning.
First I just put the collar and leash on her and let her drag around day and night. It only took her one day to get used to them. Then I started teaching her to walk on leash (I live in a flat and I have to walk her daily to eliminate and exercise). She resisted and wouldn't move, so I would make a few steps, put a treat on the floor next to my foot and slightly tighten the leash. She would then approach and get the biscuit. I repeated this until she started walking next to me. Then she started pulling since she didn't know how to heel or walk on loose leash, so I tried a few things.
First, I always had treats with me and would reward her whenever she walked close to me on a loose leash.
Second, when we walked, I would make a huge step and then stop and hold the leash firmly. She'd rush forward and correct herself, then she'd stop and I's reward. I did this in silence, no commands or warnings. She soon learnt that we only walk one step at a time. After a while, I would increase the number of steps before stopping. Then I also added the automatic sit, and a verbal cue, so now when I say "stop", she sits next to me.
Third, I would call her name and change direction every time the leash got tight and go to the opposite direction, so she had to follow. I'd offer a reward and praise as soon she caught up with me.
Fourth, I would walk between parked cars which meant changing direction often, every time calling her name so that she knows she needs to pay attention.
I have also used a prong collar since I'm not the only one who walks her, and she isn't so disciplined and obedient with others. So I conditioned her to wearing the prong collar and worked on leash pressure, and now she can walks without pulling 99% of the time.
I am sorry if this message was too long, but I hope I could help at least a little. Good luck and all the best.
Nebojsa, Serbia