Here is a link to a very quick and basic tutorial on --->
how to apply a texture map.
Made for 6.6 but it's the same in Model side.
A Model/ Lightworks material consists of the combination of 4 channels:
Color: This can be a plain color, a color shader, or a photo texture.
Displacement: This simulates how smooth or rough the surface appears by using a texture bump map, or a displacement shader.
Reflection: This channel controls how shiny or dull a surface appears. Uses shaders, can be masked using multiple texture layers so that some areas of an object are shinier than others
Transparency: This channel controls how transparent an object or texture layer is.
Materials can be a single layer consisting of the above 4 elements, or it can be multiple layers-
for example, a plain color overlaid with a photo texture layer, using an image mask to allow parts of the lower layer to be visible.
A
Shader is a mathematical method of depicting a surface. These range from simple, like the solid color, to slightly more complex, like the cloud shader, to very complex, like the ShaderLab set of shaders.
Once you have a material loaded into the Material Editor, it will show up on every new object that you create. This is why the fish texture that you mentioned in the other thread keeps popping up.
To reset the material to default, right click on the preview sphere and click 'reset'
For a detailed explanation, see Chapter 6 in the PDF manual, which will get you familiar with more of the terms, workflow, and tools.