oil change interval

First time posting, but I've tried compiling as much information as I possibly can for this post to hopefully not waste everyone's time. Vehicle Year - 2012 Vehicle Model - LaCrosse Vehicle Trim - Premium Engine - 3.6L V6 (Flex Fuel option, but has never been used by me.) Mileage - 118,978...

Bought a 2016 Encore this past week. Owners manual does not specify synthetic or regular oil, or oil change interval with respective oil type. Display has a "remaining oil life" display but shows % remaining. I am old school and want to know the appropriate miles for regular or synthetic oil...