Hi Abby!
Are you familiar with the Save The Cat beat sheet (savethecat.com)? If not, wow, I hope you enjoy digging into this great resource! If so, then you may be familiar with the Beat Sheet and how it maps out where major story beats should land in a manuscript. In fact, the Save The Cat creators even made a handy little tool to help with that.
Down the right side of the Save the Cat website's homepage, there is the SAVE THE CAT! BEAT MAPPER. Consider plugging in a standard chapter book page count (or even word count) to get an idea of where these major story beats might land in your book and how that could inform your chapters.
I hope this is helpful!
All that said, I really do think that stories are unique in following their own pace and rhythm. So while there are tools like this and other templates to guide you, "best practices" are only best until something better comes along. Follow what's natural for your story.
Best of luck! I hope your story is coming along well!
D.W. Hudson