Are there PVP or Guild elements in Arknights?

There are no PVP/GVG content in this game so far. Arknights is a story driven game and it's played on your own. Please take note though that this may be subject to change in the future. The only content that involves other players are adding friends and recruiting their support units. Once you have a reception in your base, you can then use this to visit their base as well.