You may have some diarrhea issues adjusting to the foods and liquids in Venezuela. You should preferably buy bottled water and not drink from the tap, but iced drinks and salads are generally fine (depending on the water supply quality of your native country). Be careful with expired foods and cheeses that are many days old. You usually find street vendors by highways, who sell food and who don't always have much knowledge of hygienic food handling practices. Use common sense when selecting what to eat in the street.