Buying advice for a 2017 Denali - what to look for?

[2015LTZ]

Hi all, i am looking to buy a 2017 Yukon Denali. It has around 60,000 miles. Still with the first owner. I will do a test drive tomorrow.
What are the known issues with it? I understand it has the 8L90 which is prone to issues?

What should I be looking for and what immediate things are to be done if I go for it.

I am based in Saudi. The car is a middle east spec car.