This tutorial will cover creating a transparent window effect allowing you to see through windows that you create. To do this the first thing that you need to do is create a new material. Set the Rendering Mode to Transparent. Then in Albedo select the color selection. Set the alpha to around 47. Adjusting the alpha will change how transparent it is.
Next, add your new material to your objects mesh renderer.
This is a quick way to add transparency. Remember you can adjust the alpha setting on the color of the material to adjust the transparency.