I need help with making an edit

Hello! I'm trying to make a video for a youtube channel. What i need help with is how can i make this type of edit?(name of the edit:Attack on Titan Sundays) The edit can be found in youtube. When i put my video on the tv the girls head disappears because of the video i put there. How can i make my edit like the one i said? I want to put a video on tv and the girls head should cover some parts of the tv. (Sorry for the bad english)

The best advice I can offer is to go through the training manuals for Resolve, found below.

https://www.blackmagicdesign.com/produc ... e/training

At the very least you would have to create a tracked mask of the girl over the tv screen. This is something you would do in Fusion. You will have to find a tutorial on YouTube showing how to use masks and tracking.
This is not something I have done myself.

Thank you all for your help. I have managed to do it