I think you would need a whole year of museum visiting just to have a glimpse of all pre-Roman civilizations in Italy.
The Museo Sannitico in Campobasso (
https://www.musei.molise.beniculturali.it/musei?mid=208&nome...) is one among them.
Everyone forgets about the Samnites, who required Rome to fight 70 years before getting rid of them!