Tons of reasons for coughing, to many to go over again (although I am PG sensitive and too much makes me cough).
Unless you have a sensitivity to something and don't know it, new vapers especially detoxing or transitioning ones, should expect to cough, period. Unless it's extreme (in which case I guess different setups, liquids, heck even TC could be tried) I think new vapers should expect to cough a bit.
I also found, via my most recent relapse, that even a VERY few amount of cigarettes combined with vaping will make me cough usually only first thing in the morning and not all that much, but yes, coughing.
It was kind of a useful motivator to get rid of that "oh so harmless "one" cigarette of the day," because it was pretty consistent, and if I didn't smoke one day, I would not cough. If I smoked even ONE cigarette, it was wise for me to expect some early a.m. coughing period.
I know my lungs are probably far from the most robust lungs on the planet, due to my almost COPD but I was realizing I was undoing all my progress, etc.
Two weeks in and not smoking and still coughing a ton? Well, you can certainly make experiments with eliquids, nic, flavors, setups and temperature BEFORE then if you want to see a difference, but the first few weeks or so I'd almost expect it.
Anna