Sort of related, do we know what the Celts of Gaul called themselves and the region they lived in?

I've only ever seen Gallia and Celtae, but both of those are clearly Latin.

Sorry if this is in the wrong place, but I figure an expert on the Celts in Britain would have at least a passing knowledge of the ones on the continent.

The earliest writings that are putatively Welsh in origin (Nennius, Annales Cambriae) are in Latin, so the Anglo-Saxon kingdoms are the Latin ones:

Regnum Orientalium Anglorum (Anglia)

Regnum Orientalium Saxonum (East Saxons => Essex)

Occidentalium Saxonum (West Saxons)

Australium Saxonum (South Saxons)

Regnum Cantuariorum (Kent)

Nordanhymbrorum (Northumbria)

Mercia

Smaller groups would be the Dumnonii (Devon), Cornovii (Cornwall), Deiri, Bernicii, Niduari etc.,

There are some later Welsh texts that talk about them but they're past the Anglo-Saxon era.

Edit: formatting