At our AGM last year Sara McGourty gave a presentation about what GIS does .. see here
At the first heritage cafe in January she outlined a bit about how the 4 days of training would pan out
If you would like to do some background reading before the course here are some links ..
this is NOT necessary, simply choice
A Gentle Introduction to GIS — QGIS Documentation documentation
BAJR Archaeology Guides
An Absolute Beginner's Guide to QGIS 3 (youtube.com)