Hi -Coming to Mexico City in March for a concert at the Auditorio Nacional. Even though I am from a big city and a bit adventurous, I am a little nervous, female traveling alone (don't speak much Spanish though I try), and have heard stories about taking cabs at night. Want to be able to walk to/from the concert and be in a fairly central location for other sightseeing by taxi, visiting the colonias. Not looking to spend a bundle. Can anyone help?