Hooo boy. Where to start with this one. I watched this series because I have a dual compulsion to watch both all the Roman things that Netflix puts out, as well as an odd fascination with rock-bottom terrible shows. This one ranks....probably right at the bottom.
With regards to the accuracy of Caesar's life: assume that literally everything in the show is incorrect in some way, shape, or form, with the original being FAR more interesting. Caesar, at 19 (when the show purportedly starts), did not work his way up from the bottom of the military, as the show uhm....makes up out of goddamn nowhere. [as noted below, he did spend some time in the retinue of the governor of Asia - a standard position for an aristocrat looking to be electable]. His father was certainly no traitor to the Roman state, Caesar's family did not lose their fortune as a result of a treason (since it never happened) - they just weren't a wealthy patrician branch to begin with. Being of an old family line, though, he was still an aristocrat, albeit not an especially wealthy one. Therefore, he was married to another aristocrat, named Cornelia. She was the daughter of a guy named Cinna, who's only marginally relevant in this story, but he (Cinna) happened to be an ally of Gaius Marius, who DID start a civil war. So, at the tender age of 18-19, Caesar's married to this high ranking lady, whose father happens to lose said civil war. He's prepping for a priesthood (not a barracks) at the time, when Sulla (victor of the civil war, super butcher-y sort of dude) tells him to divorce his wife.
This was normal in Roman politics. Because Caesar was relatively poor and pretty unimportant here, it should have been a request that would have been immediately granted, especially because Sulla was in the habit of having people proscribed - read, put on a hit list - if they looked at him funny. Caesar, though, had a big head, and was the only man to refuse this sort of request from Sulla (apparently). Repeated requests only put our young hero's back up even further, because doubling down on a stupid decision is a Thing when it comes to egotistical men, and...well, Plutarch gives an account of what happened over the next year or two.
Moreover, Caesar was not satisfied to be overlooked at first by Sulla, who was busy with a multitude of proscriptions, but he came before the people as candidate for the priesthood, although he was not yet much more than a stripling. To this candidacy Sulla secretly opposed himself, and took measures to make Caesar fail in it, and when he was deliberating about putting him to death and some said there was no reason for killing a mere boy like him, he declared that they had no sense if they did not see in this boy many Mariuses. When this speech was reported to Caesar, he hid himself for some time, wandering about in the country of the Sabines. Then, as he was changing his abode by night on account of sickness, he fell in with soldiers of Sulla who were searching those regions and arresting the men in hiding there. Caesar gave their leader, Cornelius, two talents to set him free, and at once went down to the sea and sailed to King Nicomedes in Bithynia. With him he tarried a short time, and then, on his voyage back, was captured, near the island Pharmacusa, by pirates, who already at that time controlled the sea with large armaments and countless small vessels.
To begin with, then, when the pirates demanded twenty talents for his ransom, he laughed at them for not knowing who their captive was, and of his own accord agreed to give them fifty. In the next place, after he had sent various followers to various cities to procure the money and was left with one friend and two attendants among Cilicians, most murderous of men, he held them in such disdain that whenever he lay down to sleep he would send and order them to stop talking. For eight and thirty days, as if the men were not his watchers, but his royal body-guard, he shared in their sports and exercises with great unconcern. He also wrote poems and sundry speeches which he read aloud to them, and those who did not admire these he would call to their faces illiterate Barbarians, and often laughingly threatened to hang them all. The pirates were delighted at this, and attributed his boldness of speech to a certain simplicity and boyish mirth. But after his ransom had come from Miletus and he had paid it and was set free, he immediately manned vessels and put to sea from the harbour of Miletus against the robbers. He caught them, too, still lying at anchor off the island, and got most of them into his power. Their money he made his booty, but the men themselves he lodged in the prison at Pergamum, and then went in person to Junius, the governor of Asia, on the ground that it belonged to him, as praetor of the province, to punish the captives. But since the praetor cast longing eyes on their money, which was no small sum, and kept saying that he would consider the case of the captives at his leisure, Caesar left him to his own devices, went to Pergamum, took the robbers out of prison, and crucified them all, just as he had often warned them on the island that he would do, when they thought he was joking.
And then Suetonius describes things his own way, but you can see the common thread:
In the course of his sixteenth year he lost his father. In the next consulate, having previously been nominated priest of Jupiter, he broke his engagement with Cossutia, a lady of only equestrian rank, but very wealthy, who had been betrothed to him before he assumed the gown of manhood, and married Cornelia, daughter of that Cinna who was four times consul, by whom he afterwards had a daughter Julia; and the dictator Sulla could by no means force him to put away his wife. Therefore besides being punished by the loss of his priesthood, his wife's dowry, and his family inheritances, Caesar was held to be one of the opposite party. He was accordingly forced to go into hiding, and though suffering from a severe attack of quartan ague, to change from one covert to another almost every night, and save himself from Sulla's detectives by bribes. But at last, through the good offices of the Vestal virgins and of his near kinsmen, Mamercus Aemilius and Aurelius Cotta, he obtained forgiveness. Everyone knows that when Sulla had long held out against the most devoted and eminent men of his party who interceded for Caesar, and they obstinately persisted, he at last gave way and cried, either by divine inspiration or a shrewd forecast: "Have your way and take him; only bear in mind that the man you are so eager to save will one day deal the death blow to the cause of the aristocracy, which you have joined with me in upholding; for in this Caesar there is more than one Marius."
He served his first campaign in Asia on the personal staff of Marcus Thermus, governor of the province. Being sent by Thermus to Bithynia, to fetch a fleet, he dawdled so long at the court of Nicomedes that he was suspected of improper relations with the king; and he lent colour to this scandal by going back to Bithynia a few days after his return, with the alleged purpose of collecting a debt for a freedman, one of his dependents.
During the rest of the campaign he enjoyed a better reputation, and at the storming of Mytilene Thermus awarded him the civic crown.
He served too under Servilius Isauricus in Cilicia, but only for a short time; for learning of the death of Sulla, and at the same time hoping to profit by a counter revolution which Marcus Lepidus was setting on foot, he hurriedly returned to Rome. But he did not make common cause with Lepidus, although he was offered highly favourable terms, through lack of confidence both in that leader's capacity and in the outlook, which he found less promising than he had expected.
Then, after the civil disturbance had been quieted, he brought a charge of extortion against Cornelius Dolabella, an ex-consul who had been honoured with a triumph. On the acquittal of Dolabella Caesar determined to withdraw to Rhodes, to escape from the ill-will which he had incurred, and at the same time to rest and have leisure to study under Apollonius Molo, the most eminent teacher of oratory of that time. While crossing to Rhodes, after the winter season had already begun, he was taken by pirates near the island of Pharmacussa and remained in their custody for nearly forty days in a state of intense vexation, attended only by a single physician and two body-servants; for he had sent off his travelling companions and the rest of his attendants at the outset, to raise money for his ransom. Once he was set on shore on payment of fifty talents, he did not delay then and there to launch a fleet and pursue the departing pirates, and the moment they were in his power to inflict on them the punishment which he had often threatened when joking with them.