Ujaval Gandhi of Spatial Thoughts has made the materials and data packages available for free for six QGIS courses. The materials and data packages have been released under a Creative Commons license for those interested in self-guided learning of QGIS and Python. There are five full-length courses: Spatial Data Visualization and Analytics, Advanced QGIS, Python Foundation for Spatial Analysis, Customizing QGIS with Python, and Mastering GDAL Tools. There is one short course on the free course list: Automating GIS Workflows with QGIS.
If self-guided is not for you, Spatial Thoughts also has these courses as part of its instructor-led offerings which are offered for a fee.
Visit: QGIS Self-Guided Training Courses – Spatial Thoughts