A good one in general on Orthodoxy is “Exact Exposition of the Orthodox Faith” by St. John of Damascus

Goes pretty hard into Trinitarian theology and Christology in the first 2/3rds. Sets up a good foundation. 

https://stanthonysmonastery.org/products/exact-exposition-of-the-orthodox-faith 

 Check out the Paradise and Utopia podcast or book series. Describes the history of the Church