How do I transfer all the content of my Iphone to Itunes?

I went from an iphone 7 to a 12 pro using a direct transfer method. Now, I would like to add some music and other items to my phone. Since I have not used Itunes in a long time I had to download it and install it. Once I connected my 12 pro itunes recognized it but not the apps or music or anything.

I need to transfer the info from the phone to itunes, and I am VERY wary of this process. Last time I did this Itunes wiped the phone. I think what happens is that Itunes does not see the current content on the phone so when it syncs it transfers the info from itunes (which is nothing) over to the phone forcing it to blank the phone. I am attaching a screen shot of what I get. As you can see, itunes can see audio content and apps and such because it reports it in the usage bar at the bottom, but it does not show any music on the device.

How do I force Itunes to pull from the phone and into itunes?