You don't do non-revenue training flights on full-size jetliners. It's way too expensive. You learn to fly (period) on small planes that can't hold passengers at all, then you train in simulators for a specific model, and then finally you're paired up with a more experienced pilot once you start flying it for real.

They definitely did not do the proper training that was merited here, but the proper training is not and never was flying a large jetliner empty.