Quote Originally Posted by NekoEric View Post
how do you know what to do exactly in duty finder?
Either by running them repeatedly until you figure out the mechanics, or by looking up info ahead of time. (But if you want to learn them in-game while running them, it's better to go in with a group of friends who know that's the plan. Sometimes DF parties will get annoyed if you don't already know the basics.)

Lots of people recommend finding videos of the dungeons to learn from ahead of time. Personally, I prefer written guides, as most videos (at least the ones I've found) don't make it as clear what's going on or why. Just Google "FFXIV" followed by the name of the dungeon you want to run, and you'll find several guides, ConsoleGamesWiki, GamerEscape, EorzeaReborn, and ffxivinfo, amongst others. (EorzeaReborn has some particularly good detailed guides for quite a few of the dungeons, and ffxivinfo.com, though they tend not to have as much description, has maps with a lot of their guides, which can be particularly helpful for tanks who are expected to be able to lead the way. But some sites are better for some dungeons than others, so I just take a quick look at several of the guides Google suggests, and then read through the most detailed of them.)