Cannon cameras on the other hand, are more easily interchanged with lenses made by other companies. Additionally, other cameras, such as the Sony A7s and A6000, can use Cannon lenses. This kind of comparability is nice, if say, you buy a Cannon camera and lens, but a few years later buy a Sony camera, but want to keep using the same lens. It also means you can save some money on a middle of the road lens, made by a third party company. For example, the first lens my workplace bought for the Sony A7S, was by the company Samyang. The T1.5/35mm Samyang lens, is arguably as good as the same type of lens from a company like Cannon, but a slightly cheaper build in terms of the actual physical casing. So unless you throw the lens at a brick wall, you'll never notice the difference. But it will be a lot cheaper.
For these reasons, I personally recommend you go the Cannon or Sony route, rather than the Nikon route. But as I said, the Nikon route is fine too, but has less options, and could be more expensive in the long run.
Most any lens will do fine to be honst. I'd just look out to see that the lens takes in the light well, has an optical (not digital) zoom if possible, and has a nice auto-focus.
Taking the light in well, is crucial to a good lens, because lets face it: no light, no picture, low light, low picture.
The optical zoom is important, because it physically, zooms in. A digital zoom simply lowers the resolution. It has the same effect as zooming into the video while editing, or watching a video on YouTube, and then zooming in on your browser. You'll start to see the pixels.
An auto-focus, is handy, because if you are a Vlogger, filming yourself, you can't keep manually focusing the video as you film yourself, and you have little way of knowing you're out of focus, until you turn the camera off and watch your footage back. Letting the camera auto-focus, especially if it has a nice smooth auto-focus, will really help. If you find yourself in a situation with only a manual focus, try filming a few test shots to see at what distance you are getting yourself in the frame nicely, and then film a few more test shots, adjusting the focus between each shot, to get it right. Make sure you mark where you stood, on the floor, each time so you can stand in the same place again when you get it right. This approach is still a good idea even when you have an auto-focus, but the auto-focus helps speed it up. This was something I should have done, but didn't, when I made "Why History Matters". Unfortunately, you can see it wasn't very well focused. But all in all, getting this right just takes a little practice. :)
I hope you enjoyed this post! Stay tuned (tentatively) next week, for my post on good audio.