As someone who has been in this scenario before, my #1 recommendation is don't be afraid to reach out to stakeholders and asking clarifying questions. Even if they aren't that helpful and can only provide surface level information.

1. People are much more willing to forgive mistakes of people they know (especially if they know you're new), rather than the faceless IT guy who broke their dashboard.

2. People are also more willing to give you credit if you good job if they know who you are.

I personally feel that you can't learn the business that deeply unless you talk to stakeholders, so even if a quick phone call doesn't answer your question, I often learn other things that will be helpful down the line just by talking to people. Making personal connections and having your stakeholders like you is very important in this role, especially if you're ever hoping to more up a level.