You are trying to use the "Caption" of your button in place of the "Name" of the button. They are two different things.
To see the name of your button, Ctrl-click the button.
The objects name can be seen in the Name Box. (Left of the formula bar)
The below code will Enable
the button named "Button 1" when cell A1 is empty. If A1 is not empty, the button will be in-visible.
Private Sub Worksheet_Change(ByVal Target As Range)
If Range("A1").Value = "" Then
ActiveSheet.Shapes("Button 1").Visible = True
ActiveSheet.Shapes("Button 1").Visible = False
Right click sheet tab
Click "View Code"
Paste the code into the panel that opens. ("WorkSheet" Module)
Alt-Q to quit the VBA Editor.