Picking a Server
Most NPCs you will first encounter should be friendly.
The first mobs you see will have yellow names. They are neutral and will not attack you until you attack them. Neutral creatures become hostile when attacked, but will revert to neutral if you go out of attack range for long enough. Soon enough, you will find hostile monsters that will attack you automatically when you get within a certain range called aggro radius. Almost all your kills will come from these hostiles. Later you may find unfriendly neutrals with their name in orange. They are like neutrals, but you cannot trade or talk to them. Usually they are members of a faction and if you do quests for them or kill their enemies, you'll get reputation...