I read earlier in the thread to not neglect interval training.
Interval training is good for burning fat and losing weight, it keeps your metabolism running in high gear a little longer than just a slower, long run. But if your overall goal is distance and not necessarily speed, then you really don't need to worry about intervals. They help develop your speed a bit more than anything else.
5K is a good starting point. You can do broken miles or half-miles. Just run for a mile or a half a mile, then walk for a bit (recovery is really based on how you feel, if you are pooped, take a longer walk, if not, shorten it up), then after you feel ready, do another mile or half mile running. Eventually you can do a mile and a half run, then walk a bit, and go another mile and a half. Then soon you'll be able to run a full 5K with no walking.
You can do it, just don't push too hard too soon. You need to gradually go into it. Also, never EVER forget to stretch! Personally, I will start off by running in place for a while or doing jumping jacks for a bit, then bring it down and start a proper breathing and stretching technique. THEN go for your run. After you're done running, do a proper cooldown by jogging or walking slowly, breathing deep, then stop and do another stretch. Proper stretching prevents injury. Never stretch a cold muscle.
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