If they don't provide you with a list of the equipment that's included and not included as part of your package, be sure to ask for this.
If you're travelling on your own (versus with a tour operator), then it's especially important that you research and acquire the necessary equipment. If you choose to travel with a tour operator, they usually provide most of the necessary equipment, which is a big help. If they don't provide you with a list of the equipment that's included and not included as part of your package, be sure to ask for this.