I can't find the Health card or the Home tab. Where did they go?

The first tab is now called "Overview". What the old cards did is under the "+" on the "Log a symptom or a reading" card: look under "Connect" for "Health Records via ID Check", "Health & Insurance Portals", "Devices", "Calendar" and "Photos & Files". Your profile and settings open from your picture at the top of "Overview".