I am a beginner on Eagle. I want a make a plated hole on PCB but no any pad on top or bottom layers. Or, a plated hole on PCB but bottom and top layers are electrically isolated. Another variation is plated hole with a circle only on bottom or top layer. In all cases plated hole connected with isolated copper wire (trace). How i can do this with Eagle?
Use a via to a track and set via pad size to whatever you wish.
There will be a minimum size to obtain reliability.
Your PCB supplier will (or should) have design rules covering this.