CD, what do you need to know? I've been gardening for almost 20 yrs.
If you have landscape exp. that's a huge plus.
I'd assume they're not going to send you out with a truckload of plants and no experience, so I'd just be honest and say you like working outdoors, you have some landscaping experience, and you're willing to learn.
It's not all that complicated once you're shown how.
I'd also recommend lots of fluids, some sunscreen, sunglasses, and one of those goofy foreign legion hats that covers your ears and neck!
Good luck.