Welcome, neighbor!
Congratulations on getting your first request! Answering a client promptly will help your ranking on Rover; they keep stats on that. Once you have responded, you should set up a Meet & Greet with the client to go over all aspects of the job. Don't just accept the request without meeting the client and their pet. Find out all the details from what they expect you to do (feeding, walking, playing, etc.) , when you need to be there (if this is a drop-in job or house sitting), any other duties, and how you will access the house (key or code).
Before you get your hopes up, many Rover clients contact more than one sitter, so you may not necessarily get the job. Be positive, ask lots of questions about their needs, get to know the dog/animals, and leave them wanting you to be their pup's sitter.
Rover has some pointers about M&Gs:
https://www.rover.com/blog/sitter-res...
Good luck!