When my husband downloaded the app, I spent 10 minutes trying to figure why his IPhone 6s would not talk. I checked settings on both the app and the phone. Finally I stated the app and as I started it, I pushed and held volume up button and up went the volume. It may be the same for you.
I am Fran and I have never done anything like this. I do workout, but never practiced for a 5k or never tried to be a jogger or runner. I do have a treadmill and I have run in the past on it, but not for any events. I quit smoking over a year ago and I have a sedentary life, so this will help me get into shape. I am over 50 as well.