Pieces of it start appearing in chests or on certain corpses when you hit around character level 50. Or, you can train Smithing up to 100 and take the Dragon perk, letting you forge Dragonscale and Dragonplate Armour.
There is no Dragon Priest Armor, only their masks.
you have to make it yourself
Yes, you can obtain the Nightingale Armor again in Skyrim if you lose it. You can do this by returning to the quest "Trinity Restored," where you can speak to Karliah in the Twilight Sepulcher. She will offer you the chance to reclaim the armor if you've lost it, allowing you to reacquire it without having to replay the entire quest.
The headsman armor has no codes, anything.
You use the anvil at any blacksmith's, or you could use the Skyforge. Remember you need 100 Smithing so you can take the 'Dragon' Smithing perk.
In the game Skyrim, you can obtain dragon souls by defeating dragons in battle. Dragons can be found randomly throughout the game world or at specific dragon lairs. After defeating a dragon, you can absorb its soul when it dies.
You can repair stuff however you can't build/forge stuff
No - Light armor is leather, cloth, etc. Plate armor is considered heavy armor.
corrupt stuff is only gained trough killing players in pvp or buying from anohter player or the grand exchange. @above That's Runescape isn't it? There is no Corrupt Dragon armor in AQWorlds.
There is no "back" armor in skyrim. However some armors will include a cape, such as the Nightingale armor. There is also a mod on the skyrim nexus called "cloaks of Skyrim" that will allow your character to wear a cloak or cape.
a necklaces, you can only have one on at a time
No. Dragonborn needs Skyrim to run