Should I put an image and video tag outside any element or can I do it inside them?

Most likely it’s a bit of a silly question… But I’m just getting started!

Hi there! Your question is pretty vague. What elements are you talking about? Maybe you have some examples or references?

hello! With ‘elements’ I meant main, nav, footer… All those semantic html!

In fact, there are no restrictions on placing images wherever you like. header, main, footer, go on, why not. After all, your markup must be valid, that’s all.
And if you want to know how to do this, search the Internet, browse through some lists and you will find something to get inspired.
For example: