Here's a first level build with high Initiative;
Warforged Fighter 1
Important stat to point-buy: Dex 18.
Traits: Aggressive (+2)
Flaws: Shaky, Vulnerable
ACFs: Warforged Fighter (+3), Hit-and-Run (+2)
Feats: Improved Initiative (+4), Blooded (+2), Guerilla Scout (+1)
For a total of +18 at level 1.