Big Scene optimization

Hi all!
I am quite new to UE4 developing and I have some doubts that maybe someone could help me fix them.

I am currently creating a mid-big scene for a game project where I already have a lot of meshes, BP and other stuff placed in. I would like to create an non cut experience and I ve been looking for Level Streaming method.

My question is that if that could help me to create a non cut experience in order to clean the memory to keep the game optimized. For example, destroy or remove the assets and actors that left behind and can’t reach them again. Does the level streaming help to accomplish that?

If Level Streaming is my option, would I have to create the level again or is there a method to divide the current scene in differente Streaming Levels?

Thanks very much!