Beginner Questions

Hi, please bear with me. I am new to unreal and I have watched a lot of tutorials. I have been searching the net trying to find answers to some questions. I hope someone can steer me in the right direction. Thanks.

I am using Unreal to create Static Images.

Determining the Correct Size of My Terrain

  1. I have imported my terrain from Blender. When I run the character it is so large so I suspect my terrain is too small. I want the character to be quite small in the terrain. How do I determine what size I should make my terrain in Blender so it imports at the correct size in UE4? Any tips to determine the correct size?

Adding a Material to the Terrain
2. I downloaded the Starter Content. I dragged the grass material (see image) onto the terrain but it only added the green color and not the grass image. Why I this and how do I fix this?

How to Properly Save Landscape with Assets
3. I have a folder with my Materials, Textures, Assets etc. Does UE4 access this folder or do I need to save the materials with the project. Once I have built a landscape and added foliage and materials etc. I am confused as to how to save everything so it opens intact the net time I launch UE4? I am also wondering how where I save Quixel Assets to use in my projects. Please explain.