Newbie here looking to learn something new

[Wesley Robirds]

To start I drive by a property almost everyday that’s a old run down decent size home on top of a hill, I’ve looked it up and it’s on 5.5 acres and last sold for 1.2m but the estimate on Zillow is around 450k. Now that being said it’s off market so my question is when you see a property that you believe could be a good investment but it isn’t for sale how do you go about finding out the owner of said property and then what would be a appropriate way of bringing a offer to a own who isn’t currently trying to sell to purchase the property?