Only by buildings to expand your town ( to the left ) you'll be able to reach the survivor. So once you have bought enough buildings you will reach the trapped survivor and be able to recue him ( and receive A reward) just by touching the portal.
Match the new residents you allow in with the most suitable businesses as you'll receive a performance bonus for doing so. Click 'Hire' on any business and the top left of the screen will detail the best match.
Turn on the real geographical location feature and you'll occasionally get the chance to loot from real buildings in your local area! But You'll have to keep the truck from swarms of zombies.