I don't want to sound pessimistic, but most of these things (pet walking, babysitting, lawn mowing, etc.) are jobs usually, and overwhelmingly, done by children who are happy with whatever meager money they get, and elderly people who don't really care about money, just needing something to do. A way to do something when feeling useless, yes, maybe. But for making money? In my experience, never.
They're time-consuming, energy-consuming work, and they just don't pay. Why pay an adult stranger a real salary when the neighbour's son will smile so hard at getting 10-20 $ for it? I did pet sitting and walking. I got my rates negociated down to 5 $ per pet per day, for what amounted to several hours of work a day. My sister did babysitting too, too. She was never paid more than, say, 8 $ an hour, lower than the minimum legal wage, and most of the time, it was less than that.