So over the last few months I've been training for my first 5K. I started my journey towards a healthier life last year when I hit 250 lbs. A severe low point for me I hurt all the time and was sick non stop. Since then I've lost 41 pounds and 10 of those in the last few month since beginning this running experience.
I highly encourage you to look into either Run For God or Couch to 5K (the later is non-Christian affiliated but will give you a similar journey experience to help you find your potential). The first week is so doable. You run 3 times and do intervals of jogging and walking. It builds you and helps you find the strength and endurance to get into a 5k.
By the way I finished in 35 minutes...a consistent 12 minute mile. If you've been thinking about it NOW is the time to start. Not tomorrow....right now.