The primary area for visitors to TJ would be on Avenida Revolucion, where one can find American style shopping, Polo & Guess, among others, as well as American style eateries, think Hard Rock Café. There are a number of good Mexican restaurants, as well as shops that sell traditional Mexican souvenirs on Ave. Revolucion, but be prepared to haggle over the prices with the shop owners, it is expected. In addition to the Mexican souvenirs, one can come home with the latest In Louis Vuitton, Gucci, Prada and the like at a fraction of the prices at home - they are all counterfeit.
Most shop and restaurant owners & their staff speak English quite well, so going off the beaten path might satisfy their desire to speak the native tongue. A day trip to Puerto Nuevo, where one can feast on lobster, overlooking the Pacific for $5.00 or Ensenada for a day at the beach, might be a better bet. I personally dislike Tijuana, as it is a poor representation of the Mexican people and their culture. Since the drinking age in Mexico is 18, numerous students from the many San Diego universities visit, turning the area into a drunken party, not to mention the opinions others have of Americans. Be prepared for some culture shock, there are many folks asking for money on the street, as well as little children who will cling to you asking that you buy packages of "chicles" or Chiclets, small square gum wrapped in plastic.
The Mexican people living in Tijuana are quite friendly, many coming from different parts of Mexico in hopes of making a living in this border town, but caution is also warranted, as in all larger cities.