We Just Got the Diagnosis

My [Relationship] [Initials], age [Age], was just diagnosed with [The Diagnosis]. They live [Where They Live]. Right now they can still [Still Can]. I'm [Your Situation]. I don't know what to do first and everyone online says to do everything at once. Help me: 1) give me a 30-day list in priority order — what actually matters in the first month and what people rush that can wait, 2) tell me the questions to ask the doctor at the next visit that nobody told me to ask, 3) tell me which legal and financial conversations are urgent while [Initials] can still take part in them, and which aren't yet — as things to ask a professional, not advice, 4) tell me what to say to [Initials] about the diagnosis, in their words, and what not to say, 5) tell me the one thing to do for myself this month. Plain language, no clinical jargon, and be honest about what's ahead without being grim.