When we first adopted our dog, Pie, she was 11 weeks old and she was scared when we put her on a leash, we just had to keep trying and eventually she was ok with it, but yeah it took some time and patience.
Keep putting the leash on her and keep trying. Don't force her to walk because that could make her more fearful of the leash.Treats and encouragement and praise go a long way in teach a pup that a leash is not something to fear.
Does she know the word "Cookie"? That's how my pup starting walking on the leash at that age. "Want a cookie" and he would starting walking and focusing on me. Dangle the cookie in front of him so he starts walking and then give him one.
I used soft treats because I noticed the cruchy one would sometimes force him to stop and chew.
Great suggestions so far. The one with using a treat to "lure" the pup towards you on the leash is what I practiced with our dog, Mia. It is great to start leash training from a young age as you are...but I would NOT bring her outside at just 8 wks old. Wait until she has had her shots. Good luck : )
Putting a collar and leash on the pup in the house 24/7 is a great idea. Great to get him used to it with a minimal amout of pressure. It will help with the little tantrum he will throw when you go for a walk.
With my pup I put the collar on him on day 2. Luckily he was fine with it, I started walking him the second week after a little practice in the yard, but only up and down the block. At this point he had his second round of shots and the vet said he can go out near the house but not places where dogs congregate like parks.