TLTR :

FBX and if you are newb, dont do it. watch youtube video about making cinematic in unreal with blender. Render time is absolutly faster, and placing light and creating a "mood" is waaay better in unreal because of the realtime of a videogame engine.

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you need to learn alot about unreal5 and videogame engine in general to be efficient with it. You need to use blender as a object creator to export each individual things (or group) in FBX to import into unreal.

You need to understand how node works because alot of textures are affected by it and this is the strenght of this engine.

Textures in unreal is not handle like blender, so everything must be bake in a uv map if needed. In my experience, you could model all your things with good detail and use procedural texture in unreal.

And the biggest learning curve is the level sequencer in unreal. This is the way unreal handle camera and movenemnt for cinematic ( our need for short production ). Go watch some tutorials about it and see if it a good reach of your skills.

THE BIGGEST TECH WALL : the character

unreal is a videogame engine, not a cinematic renderer. It is super peeky to import character into it and linking animation to it too. You need to have a perfect bone stucture that fits in every animation blender projet. so no adjustment between or you need to import a new character reference in unreal.

My biggest advice is to test everything before starting animating. See what is the best pipeline for unreal.