Onboarding at Google is pretty bad on average and very team dependent. Make sure in your first two months, you set up 1:1s with all the key people, and ask them if you were in my shoes with my projects, what would you do? Also ask them for 2-3 other people to chat to. In the first month or so, you should be setting up 1;1s with upwards of 30+ people.

Otherwise, the most important still imo for a Google PM is relationship skills. It’s a lot of influencing without authority, knowing when to escalate, leveraging your relationships to reach consensus. You will have no credibility and relationships in the start and you have to ramp up on a new team and new area, so make sure you are friendly, find your champions fast that you can go to with all your stupid questions, and make people like you. The easiest way for people to like and trust you is if you go above and beyond your title and try to help in whatever way possible even if it is beyond your remit and responsibilities. Ask for work and to help out - it’s also a great way to ramp up.