Nikon can go on canon, but not the other way around. Also, I would suggest picking one system and sticking with it. You will lose money if you switch (especially multiple times), and while we all have preferences, both are capable of creating great photos and videos. For follow cams, you want something wide, like in the 10mm to 20mm range (those being the extremes). This will give you an equivalent of 20mm to 30mm. Realistically, you should use your kit lens at 18mm, then get a 28/30/35mm (pick one, not all three), and a 50. I'm not super with Nikon, but I know they made a series e 50mm pancake. Not the greatest lens ever made, but very sharp, and very cheap. Check her and keh.com for deals on vintage glass. There is no af/exposure, but this is typically preferable for video. I have used the series e 50mm (my mother had it for her film camera), and it gave great results for photos on a 6d. Save some of the extra money until you can afford more than the kit lenses, and in the meantime look into a DIY stabilizer, then extra memory cards and batteries, and a decent photo bag of you don't have one already. I use an ICU that looks like a lunch box and a small camelbak, and while it may seem expensive, it is worth every penny and you will wonder why you used anything else before. Everything is organized and can be accessed quickly. This is turning into a nice wall of text (sorry, on a tablet), so ill stop here and then you can reply or pm me if you have questions.
