You need supplies to keep you going. When searching, Resource Bundles are big sources of much needed supplies, you can return them to your Home Base however only one can be delivered at one time, but you can mark the Resource Bundle you have left and return to it when you can.
The survivors will need Medicine, Food, Materials, Ammo, and Fuel. The handy Journal will indicate how much you need to use in a day-to-day basis. Naturally, more survivors require more supplies. Food and Medicine are of utmost importance, but Materials are much needed as well when you need repairs for your base in order to fortify your defense.
To find Resource Bundles much easier, go to The Journal and select Radio Room at the Home Page. The second option until the last option will be for finding different types of caches. About 10 minutes will be the turnaround time to generate a cache location.