Multiplayer messages can help guide you in tricky areas or alert you to traps or items nearby. If you’re following this guide meticulously, you may not need these messages quite as much, but it’s handy to have a visible warning on screen when you approach a dangerous area. The more Bloodstains and message you see, the more danger you should expect.
PvP gameplay is possible in several ways. You can join other players to aid them, request aid for yourself, or invade other players directly.
PvP is often forced and freeform (that is, someone is invading someone else, the host player may or may not have co-op help, the fight occurs wherever the host happens to be). It can be structured, and there is a dedicated community of PvP players who often look for straight duels (rather than “ganking” random players). If you simply enjoy PvP combat, period, keep an eye on online forums so you can find the level ranges and locations where intentional PvP tends to occur.
Finally, Covenants are an in-game system designed to support both PvP and co-op play. They provide in-game rewards of equipment, and they give some basic structure to PvP combat. Covenants can be joined freely once discovered on a playthrough. The early Covenants focus on PvP protection for new players, PvP hunting for slightly more experienced players, and co-operative play. Most of the Covenants accessed later in the game are focused on PvP in one form or another. They either simply actively hunt other players for trophies, or they “defend” a specific area in the game against interlopers in a location that the Covenant values.
Covenants (and indeed, the entire PvP and co-op system) are completely optional. You can play through the entire game without outside interference if you choose, but if you are interested, participating in co-op and PvP gameplay can be rewarding and entertaining.