How can I show names and values beside the sliders?

Enable Show slider labels and values under Settings > Menu > Menu Appearance & Behavior. The labels identify the adjustments, and their values show the current settings.

This is especially useful when several Image Adjustments or hardware-control sliders appear together. For the meaning of each adjustment, see Image Adjustments and Device Control.

With labels enabled, you can also enable Show brightness slider nits values when supported by the display’s controller and configuration. That adds the luminance information available to the app. It is not a measurement of the physical panel. See menu appearance settings.