If you want to copy an entire track the simple way is to duplicate the module itself that represent the track (with Ctrl+C, Ctrl+V  or  Alt+mouse drag) then connect it to the other sequencer:

You can copy a part (or mulitple parts) from a track, too.  Enter the Sequence Editor and select the desired part (right-click):

Press Ctrl+C.
Then switch to the other sequencer:

Move the mouse over the empty area of the destination track at desires position:

Press Ctrl+V

Similarly If you want to copy specific keys then select the keys (left-clicks or selection rectangle with the left button):

Press Ctrl+C.
Switch to the other sequencer.

Either create a new part or select an empty are within an existing part.  Make sure that there is enough room for the keys to be inserted.
Move the mouse over the position you want to place the first key at:

Press Ctrl+V

That's it.

If you have a vector or rotation track with multiple curves you can copy/paste keys from all the curves simultaneously.

What about working with animation parts like zooming or panning key frames and animation parts ,

Also are there any shortcut to fit to keyframes

Tracks for zooming and panning are just regular tracks with 3 curves each.  You can handle them the same way.

Fit: could you be a bit more specific?

There is a shortcut A to fit the keys vertically in the track.
Select the track itself by clicking on the left header area:

The press A.

But I'm not sure you asked about this.

I was asking how to zoom to fit track keyframes so I can work with larger numbers.

you answered this question. 

Second one about zooming and panning tracks keyframes

To zoom the value range move the mouse over the track then hold Ctrl + Middle mouse button then move the mouse up/down.
Alternatively you can use Ctrl + mouse wheel.

You can also shift the value range by Shift + Middle mouse button or Shift + mouse wheel.

The shortcut A I described above is for automatic zooming when you already have some keyframes.

You can find all the controls in
https://aximmetry.com/learn/virtual-production-workflow/preparation-of-the-production-environment-phase-i/starting-with-aximmetry/aximmetry-composer/keyboard-shortcuts/ 
in the Sequence Editor section.