How to start of filming?

I'm quite into photography but i want to get into filming. I want to start filming things and then upload them. What could I film?

Thank you

ps. I have a nikon D1300, and i'm not very confident so I wouldn't really like to talk in the film/video.

Make a documentary but make it fun.
Add music that are in the charts.
Add words on the screen after you've filmed it.

Ideas for documentary:
Society
Shopping
Animals
Nature

Check the websites in my sources, it may help.