Project Copyright question

I’m mainly new to unreal etc, and since the past month and a half I worked solo on a project.
My main question is : How do you know if your game doesn’t have copyright issue.
I mostly on my game took from the unreal templates the GeoGame the basics of it then
expanded a lot the game. I made my own music so I know no problem that part.
Everything players can see in-game is mostly stuff that came basicly with unreal or stuff that I got from the marketplace (I.E animations)
I made a lil video of gameplay to show what mostly it looks like
(Edit : im only showing the arcade, there’s other mode like campaign with multiple worlds and also I didnt reveal the most interesting mobs/boss but they mostly follow the same artwork/Mesh as the others

The honest answer is, you don’t. As long as you have the licenses for everything you are using (and didn’t pull assets from fishy websites), you should be fine.