Just wanted to throw in my experience with the game here. I've been playing on an Xbox, and so far I have had a good time. I have never had any issues with other players. I occasionally come across other people and have done a few of the random public events with them, which was actually pretty fun. Still, I have spent most of my time exploring on my own, hunting for better items and crafting plans, while taking the occasional quest. I bounced hard off of Fallout 4, but I really like the West Virginia setting better, and there is an interesting backstory with the Scorched faction that is scattered throughout the world.
I've never used atoms. They are definitely not necessary. You can buy plans and cosmetics from in-game vendors, player-owned or otherwise. Caps are harder to come across than in the strictly single-player games, but if you sell the guns you find, you'll start making money fast.