I need help with 2 things

1 were do i get Iron ingots

2ND, if i make a pvp charecter On night fall, Can it do the eye of the north quest? or only rpg charecters can do quest?

1.) Iron Ingots can be bought at the material traders in certain towns.
2.) Only PvE toons can do quests and take part in PvP as well. GLuck in PvP.

Can a nightfall charecter do a prohecy quest?

Yes, PvE characters can move freely between campaigns, aslong as those keys have been added to the same account.

Thats the fun of the different campaigns... you can take your PVE characters to each of them.

Just to clarify for your earlier question. ONLY PvE characters can do the quests. PvP characters are for PvP ONLY and can not do any quests.

Iron ingots can be bought from the Material Trader. They can also be salvaged from many drops. Usually (but not always) Iron can be gotten from "metal" items such as swords, axes, etc. You can either experiment to find out what salvages as Iron ingots or look it up on wiki.