Lou.MANUAL MANUAL MANUAL MANUAL
Manual is the key for you. Start by understanding how your camera shoots photos (photos can be a better place to start when learning about how your camera works) once you have a basic understanding of how photos are taken move to how video is shot in dlsrs. Then begin learning the 3 main parts of manual. Shutter speed, aperture, and iso. Then you should have a good enough kind of sort of beginner knowledge and it's all practice from there.
*DUMBCAN*errr yeah but maybe not so fast.
Practise is all I can say. Spend a while just reading through the menus and understanding what things do, what different modes mean etc. You learn things far better when you find them out yourself.
There is no substitute, no youtube tutorial, that will make you a better filmed. They may help, but they won't make you better. Get out and film, that's how everyone gets good. Doesn't matter what, just film things happening. Anything. You'll learn soon enough how to work the camera, and what looks good.
Last thing: there's no need to buy any more kit. You've got everything from wide to tele covered, not the absolute best quality but it'll do for now and a bit longer.