when you want to develope a game you obviously have to learn a programm language like lua or c++. the engine comes with some classes like the Model Class.
just read:
http://www.leadwerks.com/werkspace/page/documentation/_/command-reference/
load models in lua e.g.:
var = Model:Load(path)
for the beginning dont use models and use primitives like
var = Model:Box(1,1,1)
that creates a box (cube) with size x,y,z = 1
default position is vec3(0,0,0) in the space