A similar question was raised five months ago. Here's the original thread. I link again the books I recommended.
The Classical World (super readable summary of all history of the classical world).
Jaeger's Paideia (vol2 vol3) (deep and enjoyable history of Greek history/philosophy/culture).
Burckhardt's The Greeks and Greek Civilization.
Geltzer's Caesar
Alexander of Macedon, 356–323 B.C.: A Historical Biography
New History of the Peloponnesian War
Friedländer's Plato
Jaeger's Aristotle.
The Greeks and the Irrational.
​
If you want to learn Latin, go to r/Latin, there's a guide on the FAQ on the sidebar and a review of all the recommended material. There's a discord group where you can ask for help and guidance.
If you want to learn Ancient Greek, go to r/AncientGreek, they have a resources thread, also, look at this.
Bart Ehrman (a secular agnostic and scholar of Early Christianity), writes the following in his book Did Jesus Exist?
"The crucified Jesus was not invented, therefore, to provide some kind of mythical fulfillment of Jewish expectation. The single greatest obstacle Christians had when trying to convert Jews was precisely their claim that Jesus had been executed. They would not have made that part up. They had to deal with it and devise a special, previously unheard of theology to account for it. And so what they invented was not a person named Jesus but rather the idea of a suffering messiah. That invention has become so much a part of the standard lingo that Christians today assume it was all part of the original plan of God as mapped out in the Old Testament. But in fact the idea of a suffering messiah cannot be found there. It had to be created. And the reason it had to be created is that Jesus—the one Christians considered to be the messiah—was known by everyone everywhere to have been crucified. He couldn’t be killed if he didn’t live."
Ehrman, Bart D.. Did Jesus Exist? (p. 173). HarperCollins. Kindle Edition. "
See also this piece by Ehrman summarizing the main argument of his book.
<strong>Robin Lane Fox</strong> (an atheist and a classical historian) writes:
"Whatever the truth of the first Easter, the Crucifixion, at least, is a historical fact, arguably datable to the year 36. It was a Roman punishment and the Roman prefect was involved, Pontius Pilate, whom we also know from contemporary coins and non-Christian sources."
^(Fox, Robin Lane.) ^(The Classical World) ^((p. 508). Basic Books. Kindle Edition.)
<strong>R. Joseph Hoffmann</strong>, a humanist scholar of early Christianity, writes in the linked essay:
"Jesus “the Nazarene” did not originate as a myth or a story without historical coordinates, but as a teacher in first century Roman Palestine. Like dozens of other Hellenistic teachers, but lacking sophisticated “biographers” to preserve his accomplishments, Jesus is distinct only because the cult that formed around him perpetuated his memory in ritual, worship, and text, while the memory of other attested personalities of antiquity, even those who enjoyed brief cultic popularity like Antigonus I, Ptolemy I and Demetrius of Macedon are known to us mainly through literary artifacts."
Even a mythicist like Robert M. Price, though arguing that Jesus may be a composite of earlier dying/rising savior gods, concludes that the position on Jesus' existence ought to be one of agnosticism, not ahistoricity. He writes at the conclusion of Deconstructing Jesus: "There may have been a real figure there, but there is simply no longer any way of being sure."
Many more examples can be furnished.
The Classical World (super readable summary of all history of the classical world).
Jaeger's Paideia (vol2 vol3) (deep and enjoyable history of Greek history/philosophy/culture), but very focused on Athens.
Burckhardt's The Greeks and Greek Civilization.
Geltzer's Caesar.
Alexander of Macedon, 356–323 B.C.: A Historical Biography.
New History of the Peloponnesian War.
SPQR.
If you ever wish to get a more systematic overview of complicated authors like Plato or Aristotle. You can consult Friedländer's Plato or Jaeger's Aristotle.
Also, a good book to consult against an idealization of Greek "rationalism" is The Greeks and the Irrational.
The is also a very good podcast "The History of Ancient Greece" that I recommend. There's "The History of Rome" that I've never heard but from which I've heard very good opinions.
The Classical World (super readable summary of all history of the classical world).
Jaeger's Paideia (vol2 vol3) (deep and enjoyable history of Greek history/philosophy/culture), but very focused on Athens.
Burckhardt's The Greeks and Greek Civilization.
Geltzer's Caesar.
Alexander of Macedon, 356–323 B.C.: A Historical Biography.
New History of the Peloponnesian War.
SPQR.
If you ever wish to get a more systematic overview of complicated authors like Plato or Aristotle. You can consult Friedländer's Plato or Jaeger's Aristotle.
Also, a good book to consult against an idealization of Greek "rationalism" is The Greeks and the Irrational.
The is also a very good podcast "The History of Ancient Greece" that I recommend. There's "The History of Rome" that I've never heard but from which I've heard very good opinions.
The Classical World (super readable summary of all history of the classical world).
New History of the Peloponnesian War
Jaeger's Paideia (vol2 vol3) (deep and enjoyable history of Greek history/philosophy/culture).
Burckhardt's The Greeks and Greek Civilization
Alexander of Macedon, 356–323 B.C.: A Historical Biography
Friedländer's Plato or Jaeger's Aristotle for more specific info about those very important authors.