Do I need to do anything to prepare for 3D Secure 2.0 Authentication?

Before September 14^th 2019 you should contact your card issuer and make sure your details are up to date. Some of these details can probably be checked and corrected online, depending on the card you use.
Your mobile phone number will be the most important detail to check, but all details should also be accurate. This applies to all cards you use for on-line purchases.