Prophecies

i finished NightFall and now i want to start Prophecies and i dont know where do i need to go? (and what is the first quest/thing i need to do?)

If you want to play it with a new character, simply make a new character and choose the Prophecies campaign.

If you want to play it with your existing character, go to Kamadan and do this: http://www.guildwiki.org/Terror_in_Tyria

Note that if you use an existing character you won't start from the beginning of Prophecies. You won't miss out on much, just the early stuff that new characters were leveling up in. If you want to experience this content, you'll need to make a new character.

The mission you miss are still playable if your not started in prophecy's. You need to travel to that area though and unlock the mission's yourself.

You can't do the first area of the game (known as pre-searing) and you can't do the quests before Lion's Arch. Still my advise would be to bring your nightfall character to lion's arch. Specially cause after playing the game through you might decide to go title hunting and most titles aren't account wide.

Since you're coming from Nightfall, keep in mind that Prophecies missions work a bit differently than NF missions.

First, you do not need to talk to an NPC to start a mission -- there will be an "Enter Mission" button on your party window whenever you are in a mission outpost. Many players coming from NF get confused by this at first, looking around for the NPC.

Second, there are no timed missions or levels of performance based on the bonus (standard/expert/master). The bonus objectives are separate from the mission objectives. It's usually like finding a side quest within the mission, because you find an NPC somewhere in the mission area who gives you a task that is often unrelated to the mission itself. You do not need to complete the mission to complete the bonus, so you can go back later and do just the bonus if you missed it.

You are in Lion's Arch. Talk to The skill trainer for first the quests. Look for any NPCs that has quest icons on them. Take them. These quests will run you to mission posts that will start the mission. You are coming in maybe 1/3 of the way in game. If you want to start from beginning after the searing, you will have to run North-east through to get back to Ascalon City. Guild Wars Wiki will have the maps for you to do the run.

All of this is good advice. At some point, I would also create a prophecies character to experience some of the early missions. Prince Rurik is definitely a guy you should hang out with.

i want to start from the begining
i reached Ascalon City but who do i need to to talk ??
please give the Npc name

There are no quests for you so no ! to look for. Go through Ascalon City and up the stairs "in the back" and follow the path to The Great Northern Wall. That is the first mission. Follow the chain on the wiki after that.

Note that you gain no benefits for completing the missions prior to Lion's Arch other than for the titles. No gold or XP.