The Atomic Shop where you can blow your hard earned ATOMs on Fallout 76 Items a range of things. It's mainly cosmetic stuff, so things that change the appearance of your character, your CAMP and the items in it, and things to use in photo mode. These are the categories of what you can buy:

Apparel - clothes, outfits and hats for your character to wear.

Skins - skins to change your weapons, Pip- Boy and other gear.

C.A.M.P. - decorative items for your camp including things like plants and floor tiles, as well as decorative skins such as 'clean' versions of wasteland machines, or a Nuka-Cola skin for your stash box.
Styles - decorative things like tattoos and other appearance changing options for you character.

Photomode - poses, frames and other things to change the pictures you take.

Emotes - different emotes you can use to communicate with other players.
Icons - Fallout themed icons.
For the most part these items are simply cosmetic outfits and decorations. However, since launch a new section 'utility' has been added. This included scrap kits to help with crafting but, most contentiously, also feature repair kits. These instantly repair an item which some think can be an unfair advantage in a combat situation against a player without the ability to restore weapons away from a bench.

Scavenger collectron or coolers are also seen as potentially adding an advantage if you pay. The scavenger collectron is a robot that will autonomously gather scrap or junk for you, while the cooler will reduce food spoilage by 50%. These are obviously not quite as clear a pay to win advantage as the repair kits but has annoyed some players.

What is the Fallout 1st premium subscription service
Fallout 1st is a subscription service that will set you back $100 a year, or $13 (￡99/￡11.99). For that money you get a range of extra features. Some are basic like 1,650 Atoms free every month and the ability to host private worlds for you and your friends, as well as exclusive emotes and a Ranger Armor costume you'll probably recognize from Fallout: New Vegas.

However, some features have upset people. Like a Survival Tent which acts as a second base you can place anywhere. That includes a stash, sleeping bag and cooking station. It means you can have two functional CAMPs and fast travel points. It also includes another contentious item, the Scrapbox. This stores all your crafting resources and, critically, has unlimited storage, which is slightly annoying Cheap Fallout 76 Items for everyone else struggling with a full up stash.