5km (3.1 miles) is really not very far. An in shape person who doesn't run should be able to do 5km with little training. Humans are naturally very good at running.
Start by walking 1 km every day. Do that until it is easy. Then increase the distance to 2km. Then start to jog part of the way.
Depending on your physique you should be able to jog 2 km within a few weeks. Then you can slowly raise the distance to 3km then 4km then 5km.
It does depend on your physical starting point. But people close to a healthy body weight should be able to achieve a 5km run in 3 months.
Couch to 5k? This absolutely worked for me as well. Don't try to do more than prescribed though, you need to have time to adapt to the stresses of running
The Couch-to-5k program is really great and will get you there quickly.
There's a pretty fun implementation of it called "Zombies Run!!!" which does interval training with these audio stories where you have to run away from zombies periodically.