Welcome to the world of light Artorius...
I guess the first thing you need is a picture in your mind of what you want to do. A mind's eye photograph of the scene for your model or/and figures as it were.
Once there then the base. A ppiece of stable wood (one that will not warp, check or split as a result of environmental conditions). To that you will build up your ground material using plaster, paper mache, celuclay, etc. To this add any detrius, grass, buildings, etc.
All of this utilizes the limits of your imagination so good luck. I would suggest that before starting though, that you have a firm idea of what you want the scene to be as that will determine size, etc. Do not build willy nilly as you go becuase like any journey, if you don't have a destination you will go nowhere.
good luck and use the forum and its tools to help you along. Folks here are pretty generous with their advice, help and comments so you will have plenty of help. Both useful and not, but all with the intent of helping you along and making the experience a fun one.
Good luck.
Mike
Mike
"Imagination is the dye that colors our lives"
Marcus Aurellius
A good friend will come and bail you out of jail...but, a true friend will be sitting next to you saying, "Damn...that was fun!"