How does steemit actually work?

So, being fairly new to the whole steemit and DTube thing and I'm still trying to figure out exactly what it is and how it works - it seems to be a platform with the ability to reach such a wide audience with a diverse range of content - yet I'm struggling to get my head round it.

If you've got any tips, tricks or information and can help me get started, then I'd be really grateful to hear from you! :)