So what's next?
Learning by reverse engineering.
Open a rig, check what components it has in the outliner. Check the mesh, and look at the modifier stack.
Then look into the armature object.
Turn on all the bone layers, then investigate just one part of the rig.
Check the parenting, constraints and drivers (in that order)
Now that you have some knowledge about how all these things are put together, you can learn even more from looking at how other people have solved their rigging problems.
Thank you so much for watching, hope you learned a lot and enjoyed yourself along the way.