This tutorial will cover how to Reflection Probes. Reflection probes add a very simple reflection to reflective surfaces. They are not great but for small things and for lower quality games they work well enough. Screen space reflections are what you want to go with if you have the time and money to add them. Screen space reflections are typically used in higher end games for consoles and PC. You can see the difference below.
Screen Space Reflections:
To add a reflection probe, in the Hierarchy create a new object and select Light then Reflection Probe.
Position the Reflection Probe on the surface that you want to reflect. Then in the Inspector for the Reflection Probe click the bounds editor.
Now adjust the bounds of the Reflection Probe to cover the entire surface that you want have a reflection.
Now when you get down on the level of the surface you will be able to see the reflection.
Hopefully you can find a use for Reflection Probes even if it is to just get a feel for what it could look like.