This may be a dumb questions, but I'm curious. First, for World War I, obviously today it is called that as well as the Great War, but after its immediate conclusion was it only referred to as the Great War or were other names used to refer to it before the start of WWII? Then comes WWII. At the very start was it referred to as the second Great War, was it called WW2 and then The Great War was started being referred to WW1 or were there any other names? And my final question when did WW1 and WW2 start becoming mainstream to refer to them? Also, I'm sorry that this may be difficult to interpret it was hard to word this question.
The First World War was not first called so only be the besetting of the second.
It was first called the First World War in 1918. The rest is taken from the usually well researched answers of QI.
British Officer Lieutenant-Colonel Charles à Court Repington recorded in his diary for 10 Sep 1918 that he met with a Major Johnstone of Harvard University to discuss what historians should call the war. Repington said it was then referred to as The War, 'but that this could not last'. They agreed that 'To call it The German War was too much flattery for the Boche.' Repington concludes: 'I suggested The World War as a shade better title, and finally we mutually agreed to call it The First World War in order to prevent the millennium folk from forgetting that the history of the world was the history of war.' Between the wars most people did refer to the war as the Great War, even though that had originally referred to the Napoleonic War. In the US, it was ‘The World War’.
Time magazine announced that 'World War Two began last week' as early as September 1939. A few weeks after the war broke out, Duff Cooper published a book of his speeches from October 1938 to August 1939 called 'The Second World War'. In 1942, President Roosevelt wanted an alternative name. He rejected 'Teutonic Plague' and 'Tyrants' War' and settled on 'The War of Survival,' but it didn't take. The US officially named the war 'World War Two' only in 1945. WW2 was often referred to as The Second Great War in its early days - and the phrase was in use at least as late as January 1959.