I've seen very good, almost professional looking videos with a GoPro Hero 2 with flat lens, but if you do want good video, you'll likely need to get a dedicated video light (or dive shallow...or film only macro life).
For now, as you're in the start of your diving experiences, you shouldn't worry about it too much until you get the hang of the basic scuba skills. If you were to use it now, you'd make sure it's hands-free (e.g., on your head or on your arm) and probably wouldn't use the light yet, as it might cause too much task-loading.