It's gonna be really hot, so pack light. Like simple tees and basic tops, and jeans and shorts. But you don't want to be too revealing; don't show your cleavage, because the men there would stare and whistle at you, especially if you are white. Wear shoes good for walking. Traffic is crazy, you don't want to sprain your ankle jumping away from swerving motorbikes wearing high heels. Besides the people are usually casually dressed or sloppy (I mean this in an objective way).
Bring your trusty diarrhoea meds 'cuz it's likely you'll not be used to the local food.