Been messing around with VR a bit while my sister is letting me borrow her headset, and found a free plugin called CONVAI that will let you add NPC's that you can customize and talk to. you can even give them a backstory. this one is a sample character, but if you'd like to check it out, here's a link to the plugin.
https://www.unrealengine.com/marketplace/en-US/product/convai