I hope you’ve enjoyed learning how to use SQLAlchemy Core and ORM along with the Alembic database migration tool. Remember that there is also extensive documentation on the SQLAlchemy website, along with a collection of presentations from various conferences where you can learn about specific topics in more detail. There are also several additional talks on SQLAlchemy on the PyVideo website, including a few by yours truly.
Where to go next greatly depends on what you are trying to accomplish with SQLAlchemy:
If you want to know more about Flask and SQLAlchemy, make sure to read Flask Web Development by Miguel Grinberg.
If you want to know more about SQLAlchemy plug-ins and extensions, check out Awesome SQLAlchemy by Hong Minhee. This resource has a great list of SQLAlchemy-related technologies.
If you are interested in learning more about the internals of SQLAlchemy, this has been covered by Mike Bayer in The Architecture of Open Source Applications.
Hopefully the information you’ve learned in this book will give you a solid foundation upon which to improve your skills. I wish you well in your future endeavors!