"Smithing (21) Yield 1 Fire Crystal Iron Ingot x1 Elm Lumber x1" what does all that mean, also is there anything special i need 2 do or be a certain smithing skill lvl?
It means that you can craft a Knife +1 via Blacksmithing. The level of smithing is 21, you produce 1 knife (yield). It requires a fire crystal to synth, along with 1 iron ingot and 1 elm lumber.
This object is a +1, meaning it's a high quality synth. Using the mentioned recipe normally yields a regular Knife, with the rare high quality +1 version crafted if you're lucky.