Depends on what you enjoy doing.
Fighting (Good):
You are a good person and you want to use your survival skills to help those in need, sort of like a modern-day superhero. You decide that you will seek out those who need help and get them to safety.
Rescue NPCs and gain there trust, then escort them to a safe building somewhere nearby.
Fighting (Evil):
You are the last surviving member of an elite government clean-up crew sent to eliminate all evidence of the experimental labs and there part in the outbreak. With the widespread outbreaks and cataclysmic events of the last few days, your mission was updated to a seek-and-destroy on any survivors in the area. With your team dead and communications cut, you’ve chosen to complete this objective yourself before finding a way out.
Simple: Kill all the NPCs. (Additionally: Destroy/Cave-in lab entrances.)
Building:
You are an excellent survivalist with advanced construction skills. You’ve decided that the time for running away is over (since there isn’t anyplace to run anyway) and have decided to build a place for you and others to call home. A simple house won’t cut it though, anyone else that shows up will need a place to live… as well as a clinic, school, storage area, and farm. Don’t forget the walls and defenses!
Build a village, somewhere remote would be best, with walls, houses, farmland, storage areas, a garage, ect.