When I started running regularly say for the past one year, I was amazed at the kenyan and ethiopian runners who are the epitome of stamina and endurance in the runners world. I came across the term cadence for the first time, when i was reading articles about long distance running over the net. Cadence is the number of steps taken per minute during a run. The cadence of athletes is very high due to their lean build and flexibility. There is ample material on the net to pour over, so I am not going to elaborate.
I started to count my steps while running for the whole time. Say if I ran for 40 minutes, I used to count the steps. This was the time, when fitness bands had come and I was not aware that steps could be tracked easily. There are wrist watch like devices which can log your cadence too. I would not suggest you to buy, unless you want to become a marathon runner and you have the fire in you. For mortal souls, a simple tracker would do and a phone and a decent running shoe would help.
Over a period of time, I moved out from counting to listening to songs which match my stride. There are lots of options on the net, where you can download songs that match your stride. This would be very beneficial and a mood enhancer. The best way to improve both your VO2 max and cadence is to gradually extend your running time. I take a days break and run alternate days. I keep a 10 k in the weekend. There are instances like rain or some work, where I am not able to run. But I am ok with that.
Personally, i feel that if you lose weight over a period of time gradually your cadence would improve immaterial of your age from a weight loss perspective. So, the focus should be more on weight loss and cadence would happen on its own. Discipline in following a routine would help in weight loss. Do let me know, if I can be of any help .