Why is there a limit to how many dog sitters I can contact in one day, for daycare or dog walking pet care?

The limit is in place to prevent spammers from creating a fake profile and then attempting to contact thousands of sitters, believe me, this has happened.

As a new owner to Rover, you should narrow your focus to dog walkers close to your home as we all hate to drive a long way, and look for those with good reviews and recent ones as that shows they are very active. Best of luck