It's all I "du"!
I'm sorry you're not able to do your chosen sport(s). It is hard to reframe your training and expectations. But it's fantastic that you have options.
You run. Transition. Bike. Transition. Run. You'll totally love the first transition. No wet stuff to peel off; no sand/gravel/grass/dirt on your feet. It is tough on the legs though. But some good training should help with that. After the first run, it's just like a tri. There is only one race that I do where we go off in waves. Other than that, it's a mass start. There may also be some differences in the run distances. An "International" du usually has the longer run first, the bike leg, then the shorter distance run. There are sprints, Olys and halfs.
The series I run in in Southern Ontario offers duathlons at all of the tri races. So I would check with all of the tris run in your area; they may offer dus as well.
Have a great season- don't forget to post your race reports.
"You can't get what you want till you know what you want." Joe Jackson
2006 Cannondale Feminine/Ultegra/Jett
2012 Trek Speed Concept 9.5/Ultegra/saddle TBD