Sokka was in the fire nation with Aang, his sister Katara, and Toph, this is the last place they need to be so they can prepare better. They are blending in easily.

Sokka was walking down the fire nation market when a girl bumps into him and he looks down at her and he was mesmerized at first sight.

I have to know her

“Sorry I didn’t see where I was going..” he says and smiles sheepishly.