Delayed Onset Muscle Soreness (DOMS) is a common response to starting/increasing an exercise program. (I am assuming that you are feeling more of a general muscle soreness rather than sharp pain?) Basically it is a sign that your muscles are doing something that is unfamiliar to them.
You talk about lifestyle change, and the most important thing is not going flat out, but establishing a regular habit of exercise. Dial back the intensity, but keep walking. As you get fitter (in as little as 2-3 weeks of regular exercise), you will find that you can do more, comfortably.
The impact of running is hard on the body, and most experts recommend building up a solid base of 2-3 months walking before transitioning to running. If you want to add some intensity to your walking, try adding some hills to your route.
It is also recommended that rookie runners (those with less than 6 months running under their belt) run no more than 3 times per week - although it is fine to do other lower-impact forms of exercise on non-running days.
The reasonable man adapts himself to the world; the unreasonable one persists in trying to adapt the world to himself. Therefore all progress depends on the unreasonable man.
| current weight: 178.0