Everyone who wants a tailwheel endorsement asks “how much time does it take?” My response is the most common answer to aviation questions, “it depends”. The endorsement is to proficiency so it’s all about how quickly one can safely fly (of course it’s mostly about the landings) the tailwheel airplane they are learning in. The answer to how long is, on average, approximately 6 – 10 hours. Potential factors influencing total training time are (not necissarily a complete list): Prior flight experience, number of models of airplane flown, motivation level, frequency of training flights, instructor ability, etc.
Even though most of the training needed for the endorsement is focused around takeoffs and (especially) landings, the first flight should involve maneuvers to learn the airplane’s handling characteristics at altitude. Example maneuvers are: Dutch rolls, box the sky, slow flight, stalls and steep turns. Dutch rolls are particularly important as they teach coordination and yaw awareness. A tailwheel pilot has to know how to use his/her feet well and be hyper-aware of yaw so any drills/maneuvers that help with this are good.
If you are going to be a tailwheel pilot, be sure you know how to inspect and maintain the tailwheel. Here is a great resource: