Apple survey of my Youtube use to enter me into a chance to win $1000 gift card to Walmart. Is it legit? or Phishing?

I doubt Apple could care less about your YouTube use since the YouTube app and the YouTube service are not Apple products.

And any of these unsolicited email, text or popup surveys are scams - at the least they are harvesting contact information for spamming you with a ton of other crud you don’t want or need. At worst, they are phishing for your identify information to steal it and use it.

All such contests are scams.