How would you tell someone in mexico that you are going shopping at an open air market in spanish

To tell someone in Mexico that you are going shopping at an open-air market in Spanish, you could say:

"Voy a ir de compras al mercado al aire libre."

This sentence translates to "I am going to go shopping at the open-air market." If you want to invite someone to join you, you could say:

"¿Quieres ir de compras al mercado al aire libre conmigo?"
("Do you want to go shopping at the open-air market with me?")