Well, that's sort of a broad question.
Adventure Mode is basically the turn-based RPG to Fort Mode's colony sim. You control a single character (or, recently, a party of characters) and explore your DF worlds on foot, as you would in most RPGs. You have skills and attributes just like your fortress dwarves do. As with fort mode, Adventure Mode is very open-ended, and most of "what there is to do" is up to you to decide. Fighting monsters or megabeasts, infiltrating dark fortresses and rescuing snatched children, becoming a vampire or necromancer or werebeast, performing song and dance at taverns or castles, or simply exploring the neat worlds DF cooks up - these are all fine and (usually) interesting ways to enjoy adventure mode.
I'd warn you, though, that Adventure Mode is very much unpolished at the moment, even more so than fort mode. Expect bugs, weird nonsensical stuff, lag, and crashes. But if you can look past all that it's very enjoyable.
what features does have the adventurer mode (for example : like a legends viewer in fortress and oversight in Civilization/world map)
- there is fast travel i noticed
As I said, this is a pretty broad question: what sort of features are you wondering about? I don't understand what you mean by "legends viewer in fortress" or "oversight in Civilization/world map." Could you maybe re-phrase these?
Also, the Adv Mode "fast travel" is really just "faster travel" - you move around on an abstracted map, but you still have to physically (virtually?) move your character(s) from one place to another; it's not "click on the location and teleport there" Skyrim-style travel.