If you know the game, you can reach lvl 60 in a couple of days. In a day, if there is double exp lucky moments on.
The endgame currently is varied, but it mainly is about sailing on a player's ship (you can have your own, it's quite affordable) to an instance, then clearing the instance and using the items you get from there to refine your gear and upgrade it to the next tier over time. It takes time and resources, but if you get bored of doing that, there is enough other things to do - battlegrounds, attacking the dungeons of other players for gold and other resources, even goblinball, or just pvp in Kingdom of Elements, Cave of Tka-Rik if you feel like just making gold on your own, without anyone interfering.
Getting in a decent endgame guild also opens up a ton of possibilities and helps a lot in the endgame. It's kind of a requirement.