This video provides a complete overview of how to calculate the Normalised Difference Vegetation Index (NDVI) in QGIS 3, making use of freely available Sentinel2 satellite imagery, which will result in a 10m resolution NDVI layer.

The video assumes you have already downloaded your Sentinel2 imagery, so check out my video at    • How to download Sentinel2 imagery in...   for a tutorial on how to do that if you haven't already.

This is part of a series of videos looking at calculating vegetation indices, so please subscribe and check back if you're interested in more!