is there a promo code for first time users?

Each sitter has their own promo code which first-time users can utilize. Once you have decided on a sitter for a stay (have done the meet-and-greet and you both decide it's a good fit), ask the sitter for his or her code.

Also, occasionally Rover will advertise a code to use (that is not sitter-specific), but I'm not aware of one at this time.