Producing Textures, Trees, Objects, on Destroyed battlefield

Where can I find examples and tutorials to create all the above in the title of this post with my own look and feel for the Destroyed battlefield of the future world and then import it or use it inside honey?  Assume I am a total beginner because I haven't even purchased unity or Honey yet..  I have been using this ramp up time to learn the Unity tutorials and they have plenty more for me to look into but I'm not finding what I want to make me want to purchase honey yet.