Some quests are tough to figure out and might require you to say something to a mob to initiate it. Others are as easy as finding a piece of paper saying "note to [enter mob name]" and you go and give that to the mob. There's a couple things hidden in a couple room descriptions on a main road outside of a major major city in Thera. It's a good example of such a quest. I know that's really vague but I don't want them to nix the quest. It's well known and I bet if you asked about it IC someone would tell you eventually.

If a mob looks like it's looking for something maybe you need to find it and give it to them. Maybe you need to ask them what they are looking for. If they appeare mad maybe ask them what is wrong or why are you mad. Maybe you have to use an item with the "use" command in a certain room. The tricky thing with some quests is you have to be the right level range or the quest.

A lot of quests are as simple as walk into room with certain mob, mob asks you if you want to help them and you simply say yes, they'll tell you what they need and you get it and give them said items and bam quest done.

I dunno, I just learn them by playing and paying attention to things and asking people about them like "wtf why is your weapon glowing in combat and where can I get one bro?".