I have a 2012 Hyundai Elantra and I am at 85,000 miles and I have changed tires once and brakes about 25k miles ago.

I’ve never changed transmission fluid, brake fluid, coolant or differential.

Do I need to? I checked my owners manual and didn’t see dates.

What should I get done at this time into the life of the car?

https://www.hyundaiusa.com/maintenance-schedule/index.aspx

Input your trim, whether it's an automatic or manual, and how much mileage, etc

Should give you the schedule, if there's anything missing, just ask the dealer or take it to a reputable and trusted mechanic

none really. oil change all u need, car should last 200km miles.

dont go to mechanic, they just will recomend things to take your money.