|Aeneas flees the sack of Troy|
The Aeneid was written at a very critical time in Roman history and had a very important purpose for the Roman people. It was at this time that Augustus Caesar had defeated all of his rivals and transformed the Roman Republic into the Roman Empire, although the Roman Republic had been an empire in all but name as John Green has pointed out elsewhere. With the dramatic addition of an imperial court and the chaos of the preceding civil wars, many Romans had begun to wonder about their identity as Romans and had lost faith in the might of Rome. In addition, many Romans, well the Romans who were in charge, were concerned with the decay of morals and increased sexual licentiousness and Rome's traditional founding myths, filled with the rape of the Sabine women, the fratricide of Romulus, and the general bad behavior of Rome's first kings, were no fit examples for the Roman people. So Virgil sought to create a new origin myth for the Roman people with an emphasis on the traditional Roman value of pietas, or devotion to duty to one's country or family, which Aeneas exhibits throughout the epic.
In creating an origin myth for the Romans, Virgil drew on the great epics of Homer, the Iliad and the Odyssey for content and if you aren't familiar with those then I'd suggest you go read them first. (Although at least with the Iliad many chapters can be omitted because of their repetitive nature.) Just as the Iliad in many ways defined Greek virtues and what it meant to be Greek, regardless of your city-state, the Aeneid extols the virtues of duty to country and skill at warfare which were seen as vital for the continued survival of the Roman state. At many points Aeneas is tempted to cease his quest to found a city in Italy that shall be the wellspring of the Roman people, especially with Dido of Carthage, but he continues on his divinely-appointed fate regardless. (Although with a few swift prods in the buttocks by the gods.) Furthermore Aeneas and his entourage do a lot of fighting. A lot. To the point where much like the Iliad it's people I have never met before getting killed by other people I have never met before and as a result have no reason to care about the conflict. I am aware I am judging a two thousand year old poem by the standards of today, but I still find it difficult to get invested into the battle scenes when it consists of one scene characters. Much like the very combat-heavy chapters of the Iliad, such scenes could probably be omitted by most readers.
Another interesting element that I noticed in the Aeneid was frequent mention of the importance to observe the proper burial rites, lest the souls of the dead be left wandering the shores of the river Styx for a hundred years. I don't think Rome had a particular problem with safe burial practices at this time, with laws prohibiting burial within city limits for sanitation purposes, but it's odd how frequently proper due to the dead is mentioned within the story and people go to great lengths to retrieve the corpses of their comrades and provide them proper tombs. I suppose it is possible that observance of such rites was another virtue that Virgil was attempting to emphasize, but I have seen no such statements in the extensive interpretations of the Aeneid since its creation.
While the Aeneid is firmly cemented as a "classic", I think it's really only interesting to people who have an interest in classical history or mythology and doesn't have as much to offer to modern audiences. While duty to one's family and country are admirable traits to an extent, taking them to selfless levels can have dire consequences. If you're interested in Rome then I'd recommend looking at it, but for the most part it can safely be ignored.