thank a lot for all the advices
I was thinking that lense Nikon AF-S NIKKOR 50mm f/1.8G would be a good starter. I gonna get the 7100 since it have more functions, better construction, should be more futur proof and use a camcorder for the video instead of the dslr so I can have a flip screen and a good auto focus to record in a confortable way. I gonna get that by next week and let you know how it is