You've chosen to visit the rainforest in March, which is just at the end of the wet season, so you'll soon notice how well the waterfalls are running and also how damp the ground is. Things can tend to get a bit slippery, too, so if you didn't bring any walking boots I'd advise you to hire some from the office. You'll also be much better off in tong trousers rather than shorts because they will give your legs more protection, and socks are a good idea too.
There's no need to be nervous of the rainforest provided that you treat it with respect and common sense. Most of the animals and wildlife are gentle and harmless. There are some venomous snakes to beware of, but really they're much more frightened of you than you are of them. The other thing is that certain plants can cause irritation if you touch them with bare skin.
Well, that's about all for the time being. The guys are here to take you and your luggage to the cabins...