My friend Dr. Andy Bannister, an RZIM adjunct speaker, has created an engaging series of very short videos on common questions about Christianity. You can see the entire playlist here:
These could be great conversation starters with a friend. Watching through the series would also be an excellent free training to see how to concisely and respectfully address common questions.
Please do share the particular ones that you find most valuable as well as any insights and questions they generate!