How to get to Nuka-World:
Visit Ciampa's Bar in Downtown, there is a note on a barrel. Read it, and on the left side of your
PipBoy map a new map marker "Road to Nuka-World" will appear.

Tips and tricks:

• NW is not for low level characters, take Good weapons and equipment with you.
• Trashcans sometimes contain Glowing Fungus or Brain Fungus. They can be used to craft fungal purge.
• Use an alternate way to make a save file or use the Campsite mod and use a
  sleeping bag. Bethesda never really designed Nuka-World to be played in Survival mode, and therefore the number of beds around the NW map are very small, with section of the map not having a single sleeping possibility. I've added a few sleeping bags here and there, but not nearly enough to fix this issue
• Explosives are really helpful in many situations, make sure to craft them
• Take enough anti-radiation meds with you when you travel to Nuka-World
• There are several Power Armor Frames around Nuka-World (One in Bradberton,
  one at the Military Convois, and one in a small building near the Power Plant). There are also enough Fusion Cores scattered around the map. Use the PAs to gain a combat advantage against locations with many enemies
• The World of Refreshment is a good place to get some meat to cook food
• The Red Rocket at NW can be used as a settlement
• If you are insane, you will find hallucinations, be careful when you find them
• There are several small stories which are told mostly by multiple notes and journals
  

• World of Refreshment: Food Source
• Nuka-World Parking Lot: One of them has a bus with some lore
• Red Rocket: Settlement
• Bradberton: Has some lore
• There also is a radio signal that leads you to a location
• Nuka-Town USA: There are two important things there: A key, and lore from two storylines of this mod
• Fuel Station: Has a key for Nuka-Town
  

• There is a key in The Parlor at Nuka-Town. TO get there you either need a key or use a side-door with a difficult lock.
• They key can be used to open a door at the Transit Station
• Go into the NW Access Tunnels that can be accessed from the unlocked parts of the Transit Station
• There you will find another key, which can be used at the galactic zone
• At the galactic zone you will find a key that can be used in the train that is at the NW Transit Station