Spanish Translator and Teacher

I'm here in Oaxaca for at least another month and am looking for someone to help me navigate (act as translator) some basic task here like shopping as well as to help me learn a little Spanish.

I'm flexible but my basic thought is that I would need someone for 5 to 10 hours a week, to go shopping with me and then spend several hours a week walking around the city with me, telling me what you know about the area and speaking to me in Spanish.

Thanks