After updating, one of the first few things that you may want to check out is the system-wide Night Mode that you can customize to your liking. Beyond that, there are several UI changes that are generally more pleasant to the eye, even if they may take some getting used to.
The update is slightly over 1.5GB in size, so you might want to download it via Wi-Fi or unlimited mobile data plan. If you didn’t receive any notification regarding the update for your phone, you can manually check it from the Settings screen. Don’t fret though if you haven’t gotten the update yet. Since the rollout has just begun (to our knowledge, that is), it won’t be long before the update reaches your phone.