Yes, this is a RTFM question!
In D you will by default start in second, but can kick down to first (with a bit of a bump, normally).
What TFM does not make clear is that clicking from D to 3 on the selector will make the car use 1 to start and then select 2 and 3, much like a sport-auto mode on many modern auto boxes. This is really useful if you are driving around town and need to zip out onto roundabouts and in and out of traffic, because it is faster and smoother than the D-position drop down to first. It is also good on B-roads, when the normal tendancy of the 'box to change to top is a bit of a pain.
BYW, my present car is my fourth Porsche, a Tiptronic 964 (the previous cars were all manual) and I have had manual Loti, BMWs, MGs, etc. I live in rural Wales, so most of my driving is on rural A and B roads. I am absolutely convinced that a Tiptronic car is in almost all conditions better than its manual equivalent for fast driving in real life. The architype is sitting behind somone doing 50 mph for a couple of miles, then there is the clear straight. Bang your foot to the floor in a Tip, and you are in the right gear half a secold later, and blasting past. Brilliant!
However, this really is Scooby country around here! The Young Farmers in a well-maintained Impreza (or even an old pickup) are to be treated with the greatest respect ;-)
A