A new starter’s first morning goes wrong most often because nobody told IT they were coming (sample note).
A week ahead, send three things: their name and start date, which team they join, and whether they need a laptop or use a shared desk. That is enough to set up the account, the email and the shared folders.
On the day, the laptop should only need a sign-in. Everything else, from printers to Teams, arrives on its own within the hour.