Canned food is one of resources that are required for certain activities and equipment purchases. You can get them from friends, as well as buy at the game store.
1. Check if you have friends in the game. If you have friends in the game but they are not visible in your friends list, it is most probably a social network error. You need to report the issue to the help desk of the social network.
2. Ask your friends if they had sent you canned food. Perhaps they have not.
3. If they had sent you canned food but you had not received it, you should report the issue to the help desk: https://nexters.zendesk.com/anonymous_requests/new
Regards, Nexters Support Team