This is a great task and homework assignment. Get students to use a set of questions (make them in class) and interview an older person they know. A neighbor, a grandfather, grandmother, a friend of the family …. doesn’t matter.
After, they bring the answers back to class and then introduce the person to the class and talk about that person. Even possible, students can video tape their interview with their phone!
Here is an example of a pre-made set of questions. See this video on ELT Buzz Video.