https://simplicity.com/mccalls/m8337

This is a decent basic pattern, and currently on sale! It only goes up to size 22 though.

https://www.amazon.com/Hanfu-Pattern-Making-Imperial-DUONG/dp/B086PMNMKL

This book is available digitally and could work if you’re comfortable creating your own patterns!

Otherwise, you can try looking up Hanfu pattern/tutorial (again if you’re comfortable patterning from an online pattern rather than a physical one!)