nightfall to otehr campaings

What town on NF do i have to get to in order to make it to factions or prophcies

Also on prophecies/factions what town to get to nightfall

Consulate Docks (via Kamadan). Mhenlo should be there with two quests. One about trouble in Cantha, the other about trouble in Kryta. After accepting the quest(s), he'll offer to take you to the appropriate campaign.

It's probably understood, but just in case, you MUST own the original campaign in order to get to Tyria, and you MUST own Factions to get to Cantha.

and getting a run to consulate docks won't be enough, you actually have to get there yourself.

To further clarify this, you will be told when you enter Kamaden that in order to get to Factions or Prophecies from the game to see these particular people. However, you will not be told anything until such a time that you have completed a certain number of quests and are deemed ready to go by the game.

There is one other way. At the very top of the desert on the left side of the map there is a passage to the crystal desert portion of Prophecies. You can't get there without riding the worms and if you come from the Prophecies side you can't get in unless you have "worm-riding ability" and have the Nightfall campaign.

As per what Griff Mon said, you also have to have had the character already visit Amnoon Oasis. It is a route to Tyria, but only if you've already been there.