I imagine not many civilians had flying experience. When they drafted you, did they only take the small amount of people who had experience or did they train people with no experience?
Training did indeed start from scratch, basic military training, aptitude tests and classroom lessons, then flying training for successful candidates.
The USAAF and RAF had broadly similar set-ups, varying slightly over the course of the war. Firstly primary/elementary training ("ab initio" in RAF parlance) in biplanes like the PT-17 Stearman and Tiger Moth, then moving on to monoplanes like the Texan/Harvard. As a final step before squadron service, Operational Training Units (OTUs) were equipped with the same (or at least similar) aircraft to those in active service, with instructors often being veteran pilots rotated out of combat after a full tour of duty.
There's a brief summary of the RAF process on the [RAF museum website] (http://www.rafmuseum.org.uk/research/online-exhibitions/taking-flight/pathway-to-pilot/second-world-war.aspx), with a [handy diagram] (http://www.rafmuseum.org.uk/images/online_exhibitions/Pilot-Progress-1944LG.jpg), and a rather more comprehensive treatment of the USAAF in Section III of [ The Army Air Forces in World War II Vol. VI: Men and Planes] (https://www.ibiblio.org/hyperwar/AAF/VI/index.html), also with a [handy diagram] (https://www.ibiblio.org/hyperwar/AAF/VI/img/AAF-VI-img568.jpg).
