The following page of the guide to The Last of Us 2 provides a spoiler free walkthrough for the game's prologue, which takes place in Jackson.
The past - Joel
You start the game as Joel, who briefly narrates the story of The Last of Us. Then your job is to get on your horse and follow Tommy into the town.
During the scene with Ellie, you will teach the girl how to play a guitar. Swipe your finger across the touchpad and select the right chords.
Present - Ellie
After the scenes, you move on to the current events. As Ellie, put on a jacket and take your journal and a knife stuck nearby. Follow Jesse and admire the view.
Go into the bar and talk to Maria and Seth. After the cut-scenes, you will have a snowball fight. It's a nice tutorial that will help you get used to the controls and combat. Throw snowballs at the kids.
Follow Dina to the stables and get on the horse.
Walking through the snow
Now you will move on to another heroine. Follow the man through the snow and other obstacles. The whole sequence serves, e.g. to teach you how to navigate the game's world. You will eventually reach the mountain from which you can see the city.
When the man leaves, Abby decides to follow the road alone. The path is linear and quite straight - you will have to do a few jumps, crouch to go under a branch, etc.
There is also a QTE sequence when you reach the bottom. You have to push the square to get out of the grab. Use L1 to perform a dodge and Square to perform a melee attack. Dodging + melee combat is a good way to eliminate weaker enemies, although at higher difficulty levels such a solution is quite risky. Remember that Abby has a pistol on her and you can always shoot your enemies.
After the fight, use the health kit to heal Abby's wounds. Then climb the boxes and enter the building. Take the ammo and then crawl under the planks. Shoot an infected person who crawls at you.
Get out of the building and get down below. Squeeze through a narrow passageway to enter the next house.
Inside, you will find an infected - you can kill the enemy quietly, using the listen mode and attacking from behind. Search the rooms for supplies and quietly go downstairs, where you will find another two infected people.
Once they are dead, go outside the garage, jump over the fence and walk forward. You will come across more infected - try to eliminate them quietly.
After the fight, walk under the wagon, walk a few steps, and you will end Abby's sequence.