Its a common question: How do you put more than one material on a single object?
Well it’s really easy and something that you pretty much have to know in order to produce anything *half-decent (usually)
Simply click the ‘+’ button on the right of the materials tab
Then click the ‘New’ button
It’s always a good idea to name your materials so that you don’t get confused in the future
Now you have a second material, you simply have to tell Blender which parts of the object you want to have the new material
So go into edit mode (press Tab) and then face select mode,
and select the faces which you want to have the new material. Then, with the correct material highlighted, click the ‘Assign’ button.
If your materials have different diffuse colours, you’ll notice that the faces are different colours in the viewport as well
If you’re still confused, let my try show you in a video: