I will be new to duathlons this year as well. I have perused several training plans but really am doing my own for now.
Right now I am in base training mode, where I am working on each component separately (I have started throwing in a short brick once a week though and I really like it). I am working my running up to 10k and my cycling up to 30 miles. My planned second phase is to maintain my endurance and build speed, and my planned third phase is to integrate more training that simulates the actual races. My first race is not until June so I have time. My races I have signed up for this year are 1.5/10/3.1 miles and 2/19.5/3.3 miles.
Your race sounds pretty fun and optimal for someone like me. I am worried about running after biking! When is your race? What are your goals for the race?
2007 Trek 7.2 FX
2015 Felt F85X with Specialized Oura seat, Specialized Road Pro II handlebars, and Look Quartz pedals