In this tutorial, we'll go over the steps on how to extrude your polygon dataset in QGIS. The dataset I'm using has height data, but we'll go over the steps on how to extrude your polygon dataset if it doesn't have height data.
Helpful links:
Add basemaps to a QGIS project - https://youtu.be/Z-u4AiDj6XA
How to add Open Street Map data to your QGIS Project - https://youtu.be/5-jIsIVeaA4