I really like Fallout 76 finally, it took a long time but I truly enjoy playing now. It's less building than fallout 4 but still enough to have fun and keep you occupied while you're not doing quests and events. I love the Atomic Shop that always updates with new stuff you can buy, like weapons, skins, settlement objects etc.
The map is also very large and filled with a wide range of enemies with more always being added. The map also gets bigger and changes overtime with new regions that get introduced. You can also have 10 camps or "settlements" that can be built almost anywhere on the map but with only 1 active at a time. Camps may feel small compared to Fallout 4 settlements bc they're essentially designed to have 1 large structure or home built in them. Building shelters in your Camps artificially gives them more room by adding an underground bunker you can also build stuff in. It's smart to build camps near resources that can be mined with special machines you can build.
You can also take over a workshop when you find one. This grants you access to that area which usually contains some resources that can be mined. These areas are much larger than your camps and can be built in. However, unlike your camps these areas don't save and upon exiting the game, they are lost forever. These areas are designed to just mine additional or even rare resources. Beware though, other players can come take over the workbench if you don't defend it. This is one of the few places where players are allowed to be hostile towards one another. Normally players are not hostile when they visit your camps to trade, only when you take over a public workbench.
Make sure you sell things in your camp by building a vendor stand. Camps are also very important when it comes to repairing and upgrading armor and weapons. Once you've leveled up, research what weapons and armor are the best in the game so you know what to look for.
Fallout 76 does have factions but they're not as influential imo compared to other fallout titles. Quests however are a must as they help you gain XP and unlock lots of stuff. This includes daily quests, daily ops, and the monthly rewards on top of the main story and side quests.
One of the most important aspects of Fallout 76 is working with other players to complete certain things, it's still playable solo but there's a lot stuff you can do in groups. This includes group perks too.