Yep, that's true, but that's not adding in his Base attack bonus (BAB) the standard +1 that all fighter base classes get (Barbarian, Fighter, Ranger, and Paladin)
Edit: Oops I didn't add his BAB to his offhand at stage 2, so he would be+1/-1.
Each level this will increase, so when we hit level 2, he'll be +2/+0, so it won't be long before he'll be ripping through enemies. He'll need "improved two weapon fighting" around level 6, so with a full attack he'll deal 2 hits with his main weapon, and 2 hits with his off hand. At this time his attacks will be +6/+1 for his main, and +4/-1 for his offhand.