You can align objects with one another using the Align panel (Window menu > Align) in the following ways.
align
How to align an object with selected objects
  • Choose Selection in the Align panel.
           The selected objects are aligned relative to each other.
How to align an object with the document
  • Click Document in the Align panel.

The selected objects are aligned relative to the document.

Example:
You want to put an object in the upper left corner of your document.
    1. Select the object.
    2. Select Document in the Align panel.
    3. Click the screen-shot-2018-03-14-at-14-33-19 and screen-shot-2018-03-14-at-14-33-29 buttons to align your document.