Hey everyone

I'm developping a storm chasing game for about 2 years now, and I'd like to reproduce the U.S. great plains environment. I never worked on the graphics of the game since now, so here is how my game looks like (I know, Eeewww)

Streets are blocks, and terrain is basic and ugly...
IMAGE1
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And..

I would like to make it look more like this (Grass, plains, and you can see the street):






So, I'm a real newbie with terrains and "good-looking" stuff, so what would be the steps of making it look great? I mean, I've seen some wonderful graphics here, very impressing, so I know it's possible...

Thanks!