How much to charge for dog walking bussiness?

I want to start saving up money for this animal shelter who needs help in order to make an operation on this dog so they can save the dog’s life. Don’t say ” Let them pay” I want to help and they have asked for help. In my neighborhood there is tons of dogs and I want to start walking them. The lightest one is like 7 pounds and the heaviest is 110 pounds. I do not have an idea of what to charge. The most big odgs I can walk at a the time is like 5. I went for 6 once and I looked stupid trying to walk a dog an extra dog.

How much should I charge? Please include price and size
Also how much should I charge if I walking multiple dogs?

How soon should you trim a dogs nails?

How early in a dog’s life should you start trimming their nails? My dog is 7 months old.

Is there such a thing as a permanent vaccination for dogs?

My mom claims that my dog finished taking all of his shots for the rest of his life but i think she is lying. My dog is only 1 and a half years old. Is there such a thing as a vaccination that last for the rest of a dog’s life?