It’s not always easy to find the agents of writers/books. You may have to contact the author. The publisher will be on the first few pages. Finding agents with a great resume can be sketchy too. You can do the following to find a credible agents/editors/publishers.
Attend writing conferences.
There is usually an agent and editor who is invited.
Remember that the publishing world has changed and good agents may be a dying breed. Publishers are now doing nearly everything “in House” which included creating their own books and being the agent.
You can get something like this, which lists agents and publishers and submission guidelines https://amzn.to/2KLpFeR
Either self publish or send your work to an agent/editor/publisher.
Write your story as a word document, children’s book.
double space, make sure you have a header and your information on each page.
Check out guidelines for where you want to send it
Send it to an agent/publisher that accepts unsolicited manuscripts Send a self addressed stamped envelope too
Make sure to have a cover letter with your publications/and or writing experience
Don’t send illustrations, but do mention that you have them (if you do)
Follow the 9 video course for creating and publishing a picture book at https://www.readersselect.com/picture-book-course-sample