Trying to run a 5 k

I actually just recently helped someone run a 5k. I'm not sure how long you have until your goal run but what I would suggest is going to a nearby track and begin by running a mile. Now you can slow your pace as much as you need to but NEVER walk. I think you'll find that as much as you'll feel better when you start walking, that you'll realize that you had more to give. I also mixed in after each run some basic exercises like pull-ups (if you are able) 3 sets of different ab exercises (50 reps) and 3 sets of push-up exercises (25 reps). Even though you aren't running this will just build your core and mental endurance. Gradually build up to where you need to be and continue adding quarter miles every week or so until you are running at least 2.5 miles. Then you should at least be able to push yourself for a 5k