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Simply swapping the SIM card won't download your data to your iPhone. You need to sign in with the same Apple ID, iCloud, email accounts, etc on your phone. On your new iPhone, open Settings > name at the top or Sign In > iCloud and sign in to your iCloud account.
Then open Settings > Passwords and Accounts or Settings > Mail and Settings > Contacts and then sign in to your email account there.
If your data synced to iCloud, Gmail, etc, they will be synced to your iPhone 8+
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