You can talk about the music you two like, current social events, movies in theaters or even upcoming events. You can also talk about clothes like the outdated fashion that people likes to wear or the new trends.
Ask him who his mentor is or who does he look up to as an example? Share your experiences. Ask if he has thought about being a mentor, or at least an example, to younger children. Unless there are traumatic events in his past, ask him to share his favorite childhood memory. Ask him if he were to volunteer at the zoo, which animal would he want to work with and which would he avoid.
Ask questions that cannot be answered with yup or nope. Like what is your favorite ice cream? Or cake? Ask him if he has ever baked cookies. Ask him if he would like to bake cookies at your house next time you have I'm visit.
Talk to him about what he would like to do in the future and see how he sees your guys relationship in the future,you should talk about the movies that came out in theater now and will be out in the future,life problems,family problems,friend problems,cars,vacation stories or trips,celebrities,bands,sports,funny stories,embarassing stories,tell jokes,make a list of stuff that ask him about what things he likes and get to know each other more