blender glass trouble

When you import materials from a 3D Development program, like blender maya or Cinema 4D into Unity The texture effects will not import with the model itself because Unity uses a different texturing system to the Dev programs.

The materials will import, but not material effects (like transparency for example). To get these effects you have to make the material in Unity, but this is very easy just either create a new material or select the material which came with your import and play with the settings there

To get a slight transparency (similar to glass)

Change your material Shader from Diffuse to FX>Flare this will lighten the material and give it slight transparency but sadly not give the desired glass texture from the tutorial you linked.

If u need more help texturing just leave a comment and my best advice is just to play with the Unity Textures they are pretty versatile