Short answers, pulled from the story.
Strabo wrote his Geography between AD 18 and 24, with some scholars arguing it may have been composed entirely after age 80. The latest event recorded is the death of Juba no later than 23 AD when Strabo was in his 80s.
Strabo studied under Tyrannion, a captive educated Greek who served as a private tutor to Cicero's two sons. This early exposure to Roman intellectual circles shaped his lifelong perspective on geography and history.
About thirty manuscripts exist with the earliest being the fragmentary fifth century palimpsest Vaticanus gr. 2306 plus 2061 A. Two manuscripts in Paris provide the best extant text for different sections of the work including Parisinus gr. 1397 from the tenth century covering Books 1-9 and Parisinus gr. 1393 from the thirteenth century containing the entire text.
Book IV examines Gaul covering Narbonitis, Aquitania, Celtica, northwest regions, Great Britain, Ireland, Thule, and the Alps with detailed descriptions of cities like Massalia, Lugdunum, and Durocortorum.
The first printed Greek edition was the Aldine of 1516 while the first text with commentary was produced by Isaac Casaubon in Geneva in 1587 whose 840 page numbers prefixed by C are now standard text references.