Church History (General)
Church History is not something optional like knitting, it's as basic to the Christian study life as basic culinary skills are to life in general. Just as basic cooking isn't a gender role, Church History isn't something left in the ivory tower. Without history, you naturally drift toward a solipsistic mindset with all human history placing you as the main character. Church History helps you understand that every possible series of events we read in the news has an analogue in previous eras. It shouldn't shock anyone to learn that Christians have always had to deal with governments trying to gain endless control over the Church.
The trick to studying Church History is twofold: move from broad to specific and always have multiple sources. Speaking of the former, you need to create Church History scaffolding, then only later zoom into eras where you would like to further build out your knowledge base. Speaking of the latter, you need more than one source for Church History.
The collection of humans events we call "the past" requires an interpretation. Just as there's no such thing as language translation without in-built interpretation, there's no such thing as history without interpretation. Today the term we use for a reporter who provides denotation with a broken connotation "fake news". The same term is used when a reporter claims to be avoiding a bias. This is self-deluding at best. The same applies to the study of Church history as well as history in general. Get multiple sources to avoid problems. You need multiple perspectives.
One thing to avoid when discussing or studying Church History is back-in-my-dayisms. While this is something we must avoid in all eras of life given the wildly chaotic nature of our endlessly changing status quo, in Church History we must to be doubly careful. Incredibly often, new discoveries upend our understand of various eras in history. We can never say "I already studied the early church". We need to constantly refresh our knowledge.
For example, Zwingli has generally been read through a strong hagiographic lense, but it's now well documented that he had a mistress while engaging in his reformation ministry. It's also no secret that Luther after 1525 wasn't as balanced as he was in his youth. We can also now question the mythology of Wyclif and Hus as being our main reformation forerunners. They hardly qualify. Better research has shown Gregory of Rimini (d. 1358) to be a better forerunner, but he doesn't make for great movies. Frankly, anyone who received their theological or historical education primarily from Ligonier Ministries needs to restart all studies from scratch.
Speaking of people who wouldn't be great for the movies, Oecolampadius (d. 1531) is an incredibly interesting figure. Research has shown that nearly all of the doctrines we attribute to Calvin actually come from Oecolampadius. Furthermore, Oecolampadius' sermon on salvation by faith alone was 1512 while Luther's door incident was 1517. The person Luther debated the Supper with at Marburg wasn't Calvin, but Oecolampadius. We can thank Diane Poythress for the elaboration of these particular discoveries.
One more example should suffice to demonstrate the need to constantly update our historical knowledge. Luther's big theological break wasn't at the door incident in 1517. It was 6 months earlier. The 95 theses in later 1517 attacked finances, so it's what upset people and makes for solid movie content, but it's the 97 theses, called the Disputation Against Scholastic Theology, in early 1517, which records Luther's theological insights. So, much of the Christian pop-culture understanding of history needs rework.
The following resources are helpful building out your Church History scaffolding. See the category on Medieval Church History to zoom into the commonly overlooked 1000 year period between 500 and 1500.
History of the Christian Church (Philip Schaff)
The Schaff series is the standard. This works covers the wide range of Church History. Schaff also has regular sidebars where we zooms in on special topics like particular theological debates. It's also smooth reading. Want better stories to tell? This is a good source.
Church History in Plain Language (Bruce Shelley)
This is a simple single volume book that will give you another broad overview. The part I most like about this book is that it's in audio book. The creation of audiobooks are as life changing as the Gutenberg press. No longer do we need to halt out lives in order to ingest information, we can do it in the car or on a run. This is a solid volume to fill the air with while your eyes are being used for something else. Of course, you can just sight-read it too. There's a 5th edition coming in 2021.
Handout Church History (John Gerstner)
This is the series that got me hooked on Church History in the 90s. It's a somewhat theologically-focused Church History series. The best part of this series is that Gerstner is upfront about not being without bias. That's honest. He'll give you his analysis of events, not just throw bare events at you.
The reason it's called Handout Church History is because of the handouts. Ligonier may still provide these. I got them in paper format in the 90s. This series is part of a series of series which included Handout Theology and Handout Apologetics.