I run when chased... At 5'9 and 210 lbs I am not your typical picture of a "runner", but I now run 7.5 miles to or from work 2-3 times a week, and actually enjoy it.
Personal advice from my on-again/off-again running over the last 15 or so years is as follows:
1) Use good shoes, not worn out ones. Simple advise, but a lot of folks solve ankle and foot pain simply by buying new shoes.
2) Run SLOW. The biggest mistake I made for a long time was I would go close to full-bore and had huge troubles running more than 3 miles seemingly no matter what. Intentionally running as slow as you can will let you build up muscles and lungs and you can gradually increase the pace once you have met your target time or distance without feeling destroyed. 12 minute miles are a decent target for a healthy pace while building up, if you are running faster than that and are tiring out, there is your problem.
3) Rest and recover. If you hurt, don't run. 2 rest/non-running days between runs early on is a decent target. It is easy to convince yourself you don't want to lose progress and go out for a run despite a tweaky knee/ankle/hip/back, don't. You can quickly go from tweak to debilitating injury. Ride your bike, walk, or just plain rest if you hurt, but don't run while even slightly injured.
4) Get your distance in, even if you have to walk some of it. It is easier to go from run-walking 5 miles to running the whole 5 miles than to stop running as soon as you have to break stride and hope to build up to 5 miles (or whatever distance). Ideally you can just drop down to running super SLOW when you are feeling at your limit and not have to stop in the first place, but I know just how awful even running slow is when you are starting out.
5) Ride your bike! Building up lung capacity and upper leg strength with regular rides makes running longer distances much easier than by trying to get there by running alone. I did not run all winter, but did ride 15 miles a day almost every weekday all winter. In spring I did a short run, then a couple days later my second run was 5.4 miles with some hills. My calves were out of shape and took a few more runs to not feel awful after a run, but that is far better than how I felt last year when I had only been bike commuting about 2 days a week through winter.