The follow-up that catches problems.
IMMEDIATELY
Confirm the site loads Run AutoSSL Test mail both directions Test every form Check the checkout, if applicable
WITHIN THE FIRST DAY
Check error logs Verify scheduled tasks are running Check every subdomain Confirm redirects work
WITHIN THE FIRST WEEK
Confirm nothing is missing Check search visibility has not dropped Verify backups are running here Check analytics is still recording
FOR WORDPRESS SPECIFICALLY
Set up a real cron job. HTTP wp-cron is blocked on our servers.
Without it, scheduled posts, updates and plugin tasks silently stop.
BEFORE CANCELLING THE OLD HOSTING
Wait a week at minimum Confirm email has fully moved Take a final backup of the old account
WHAT TO UPDATE
Your documentation: where things are now, what changed.