Changing from Android to iPhone

First try this --> Move from Android to iPhone, iPad, or iPod touch - Apple ...

If that fails or you do not want to attempt or have already set up your device. then...

You can still transfer these data.

• Photos & Videos --> Upload to iCloud Photos using the same Apple ID that you have used on your iPhone. After upload, enable iCloud Photos on your iPhone. That's it.
• Contacts --> Contacts are not stored on an iPhone nor on SIM, they are synced to  Google, iCloud, AOL, Exchange, Outlook, Yahoo or any Other. Upload all your contacts to any of the above email client server.
• Any Specific Files --> Upload to Cloud Drives (iCloud Drive, Google Drive, OneDrive, DropBox, Flickr, box, AmazonDrive, Adobe Creative Cloud and Use Files app on iPhone
• Apps --> In any way they have to be re-downloaded using the App Store.

Have you tried --> Move from Android to iPhone, iPad, or iPod touch - Apple ... and selected WhatsApp and its history, if that is permitted.

My experience says you can't transfer because on Android, WhatsApp, chat history is not stored on iCloud, on iOS it is.

That may be possible with third-party software. Warning!; WhatsApp data through third-party software has the risk of data being compromised. Because the data will be churned through third-party servers, which may or may not be encrypted. Be judicious while selecting the software and taking this call.

WhatsApp is not an Apple product. Contact the app developer here --> App Support or WhatsApp FAQ or Restoring your chat history - WhatsApp FAQ