You will have a blast!!
I am a fan of Jeff Galloway. You can google him and get an idea of his training methods. I read many of his books early on...I was new to running and older (but had my health!) and was never a runner when I was younger.
I have two planned this year
The May Cleveland 1/2 got me motivated through the winter and the September CCFA's Nashville Women's 1/2 because I've always wanted to go there!
You'd be surprised to find out the people you know on a daily basis that have ostomies or j-pouches...I worked out with a woman for a year before we both figured out we had had colectomies and the same CR Surgeons!!!