These tours are adventurous, bring some good shoes and a camera, a waterproof would be ideal or a cheap one, since the canoe rides on most of our Expeditions can be splashy, also there are sometimes some humidity.
Walking paths are more or less clean, and I would probably suggest some light shorts and t-shirt, bring a towel in a waterproof bag or plastic bag, you might be a little wet, but it is warm here and you dry quickly.
There are no really insects, but bring some spray anyhow.
Now you might like to swim and there are nice spots, including walking underneath waterfalls, therefore I suggest light clothes, or in the end just beach wear.
Light long pants are nice when walking in the dense Jungle.