Just echoing what others have already said.
I started a "couch to 5k" program last October, in the hopes of being able to run the CC5k on our cruise last week. My first day of the program, I couldn't even complete a 60 second jog, and I'm proud to say that I was able to jog the entire 5k course without walking (even if I was as slow as molasses, and my jog was barely faster than other people's walking pace). It took me 46:08 to complete, and I was nowhere near the last person on the course, although I would have been ok with it if I was.
Even being Pooh sized (although not nearly as Pooh sized as when I decided to change my lifestyle last summer) and super slow, I did not feel self conscious while running, and a number of the "faster" runners gave me high fives and words of encouragement as they were passing me on their way back to the start. Not once did I feel self-conscious, and it's such a laid back event, that people who are in much better shape than you will congratulate you for making the effort.