CatRocks- I'm from Glasgow too, I moved to the U.S six years ago. I'd kill for a fish supper
To the O.P:
I never followed an actual c25k program however, I when I started running again I was lucky if I could run half a mile at a 4.5 pace- sad but, true! Now a year and a half later I'm running 7.5 miles four or five days per week and I'm running the VA Beach Rock and Roll half marathon at the start of Sept. I highly recommend running! I never thought I'd be able to run 7.5 miles again- not in my wildest dreams. Anything is possible, just gotta have determination, a good sports bra and some good running shoes.
Just start doing the walk/run and just keep building your running time up. Use the 5k as motivation to get out there running daily!
Sign up and get out there! It's wonderful cardio and is a real stress buster, at least for me.
Best of luck to you!