Can anyone help me with the Background/Overlays

I’m a newbie and need some help with the overlays and background since I don’t want to use the Episode originally one.

you can get copyright-free backgrounds from pixabay or pexels, and multiple other websites!

yeah, I’ve already found some but I want it to be more suitable in a fiction story

You can use that same thing. You just have to turn it into illustration so it will be cartoon like,
Just cartoonize the picture. Just search for an app. There’s a lot . I don’t know any names in particular