Hi there,
On Windows, you can bring back the sidebar that you are accustomed to by tapping the View button in the menu bar toward the top left of screen. Then click Show Sidebar in the drop down menu.
Without this option selected, any devices plugged in to the PC will show up in the upper right hand corner of iTunes.
To change the name of your devices, the simplest way I can think of is to head to the setting panel on the device, go to General settings, About, Name. You can change it from there. (Settings, General, About, Name).
Best of Luck
Cheers 🙂