Ruff Day (Sixth-Grade Shape-Shifter) by Steven Scott and illustrated by Lavinia Brandizi is due in August 2025. And in fact, perhaps the whole series is. It is possible then that when reading my online reader copy I was not starting with book one. This would make sense as there are several pieces of information that are missing and are only “filled in” as almost sidebars and/or to explain to someone when they find out the secret of our main character. The premise is that our main character can change into anything he wants too (or so far it seems) and in the course of his everyday life, he will eventually turn into a dog, who is captured by a dog catcher. He learns that the Mayor has a plan about the stray dogs of the city, and then things get really weird. Overall it is funny for the younger reader, but as an adult reader, I think our hero made some inappropriate choices. But the goofy illustrations are silly and not overly busy or messy so they allow you to focus on what is happening. 
Other titles in the series are Game Changer (Sixth-Grade Shape-Shifter), Double Feature (Sixth-Grade Shape-Shifter), and Gadget Bandit (Sixth-Grade Shape-Shifter). I did some research to see if they have an order or it is free for all and I’ve come to the conclusion that Ruff Day might be the first. (This is partly because the secret is found out by another character and therefore it allows for more possible story arcs in the other books) and partly because it is the only reader copy I could locate)
What is not a free for all is the way things are set up. The publisher description says that the books are for reluctant readers and struggling readers and you can see that. The pages are open, the text simpler, but not simplistic, and it is “spaced” in timing as well. It allows for a read aloud as well as solo readers and it could be something you read together. 