To improve your running performance it's not all firmly based on how fast you run, how often you run or even how far you run.
Stretching can play an important part in keeping you running, running strong and hopefully running injury free. There is and has always been some debate on stretching as to, when to do it ? Before a run, after a run, both, neither, static or dynamic.
Because there always has been so much debate, I think the best approach is to go with what works for you. In the same way everyone has their own nutrition and hydration routine that works for them on races and long runs.
I'd certainly suggest that some stretching is better than none and there is suggestion that static stretching before running can cause injury. I therefore do not stretch before a run and try to do my first kilometre of my run at a slower pace to the rest as my warm up.
I tend to do a mix of static and dynamic stretching after a run and feel this helps to break down in lattice acid and help keep me flexible. I also try to stretch daily whether running or not.
I find that a foam roller is invaluable and as fellow trail runner told me when I was having some tweaks in my ITB (Iliotibial band; it sits on the outside of your knee) roll the s**t out of your ITB. Foam rolling and use of essential oils certainly helped.
Another key component to keep running, staying strong and staying healthy is cross training. Cross training is basically using other activities to support your fitness base. This could be hiking, biking, swimming, surfing etc.
I like to bike and studies have suggested that people who do multi-sports tend to have better results with their running than just running alone.
I think the key to running if you haven't run before, is to take it slowly, listen to your body, stretch, foam roll, cross train and above all have fun.
Disclaimer: Always check with your physician, if taking up a new sport or taking up any sport to make sure you do not hurt yourself.