I got a pedometer some years ago, after I met up with a colleague who looked so much fitter and healthier. She said she'd done it by wearing a pedometer, and making sure she did 5000 steps.
I have a new one, but it's so complicated I took one look at the instructions and had to lie down in a darkened room. I read the US say 10,000 a day, and found that a bit of a challenge, unless I did a 5 mile dog walk each day.
I have foot problems currently, the physio demands I cut my walking down. I'm finding it a bit of a challenge not to feel sorry for myself, because walking is the only exercise I can do these days. Then, I think on, remind myself how many people are in a much worse position than me, and tell myself if I follow the exercises, rest the foot, etc, 6 weeks on, I'll be ok. Fingers crossed. I may ask mrIam if he can fix the pedometer, but not till I can walk properly again!