The charcters

Imagine your stuck in a bunker with limited air. The government tells you that the world above is destroyed because of the necular war that went on 300 years ago. The system has been working in your favor until one day they decide to limit your oxygen. You have been working for months to get your escape all planned out. Why escape when then the world above is dead? That's because my family will be dead either way in the next month because they won't have any oxygen left.

When you break out you travel for days and a guy around 21 takes you guys. What will happen, where did he take you, How long will you guys last up on the surface, and what happens between you and the 21 year old guy?