Just as you arrive you get the Hummer, the first vehicle in the game. You can put equipment you don't want to carry by opening your inventory while piloting the vehicle. Though the town is attacking you and the vehicle for supplies, they won't actually "open" the vehicle and take anything you put in it.
For this mission you will need long-range weaponry, as most of your enemies will sharpshoot from the roofs of the buildings. Including civilians who will throw molotov cocktails, darts, and rocks.
Throughout the mission your path will be blocked by large metal gates, each with a switch somewhere nearby that forces you to leave the vehicle. At the second gate you will find a hungry raider who will ask for food in exchange for information about a key to the gate switch. Shortly after this he will become hostile and attack. Giving him food does not prevent this from happening.
At the very end on the terrace of the very last building, there will be a raider with a rocket launcher. Better hope he misses, as it is nearly impossible to snipe him down before he shoots. You can sneak under his balcony, climb the ladder and shoot him in the back with a shotgun before he fires.
Midway through the mission you will find Phillip Wilson, a librarian who has lost his spectacles. Towards the end of the mission there will be a trunk with glasses inside which you can trade (give) to him and he will give you a book in return.
Although some NPCs in Macomb are called 'civilians', they are aggressive and Brotherhood doesn't care about their fate so there is neither special reward nor punishment for killing all, some or none of them.