7d camera, lense advise?

Been doing a lot of research on what camera to get especially with this upcoming black friday sale. I've decided on a Canon 7d and am going with the re-fubrished from canon which is a good deal and am willing to take the risk involved with gettign a re-fubrished if worst comes to worst. I've seen a lot of starters kit but have read that it might not be a good investment because the lenses that are included aren't anything great. So I've decided I will just purchase the body and invest money into lenses that will suit my need. My subjects for photography will be mostly surfing photography and similiar landscape or scenery shots as well as trying out some low-lighting and night time photography with no flash. I've learned that having a high aperture will be an advantage for low lighting shots such as night time? or indoors with no flash. I just need some advice and assurance that everything I said is correct, correct me if I'm wrong. What are key specs I should look for in a lense for a 7d that will suit my need. I don't have a whole lot of experience shooting with cameras but I am very patient and am serious about photography. Price range would be anywhere from 200-800 if it's worth the investment. I am possibly considering getting an average lense just to learn how the 7d functions and how to work differents parts of the camera? Any advice will help? I live in Hawaii so there are many great things to photograph I just want to make sure I have the right tools to maximize my shooting experience/journey. One more thing I plan on getting my camera in the water with an underwater housing, might not be now but eventually.