I have only sim time on the A320. My PIC experience includes the 737 Classic.
Going from the old lady to the A320 was an eye opener. First thing you will notice is how apparently easy Airbus has made your job. From the ingenious Flight Control Laws of the FBW system, to the easy to follow ECAM action items when things go 'by-the-book wrong', to the lights out - all is well control panel design, I think you will find your short bus experience a pleasant one. They have thoughtfully pre-programmed many of the systems tasks for you. (not unlike the 777)
It bears repeating:
The Airbus FBW and systems design make it more difficult for a flight crew to screw things up completely in most normal operations and the standard non-normals. Workload is minimised.
I have learned:
Fear not the computers and fly her.
The transition to the sidestick (I'm a leftie) was no problem from either seat.
Obey the ECAM.
If all else fails, the thing's got a bunch of reset 'buttons'. (CBs)
Green=good White=informative Amber=bad
I would recommend some sim time with the focus on non-standard (are they ever standard?) failures with an experienced crew member and take notes during any debriefings.
More (real) wisdom beyond my pittance hopefully will follow.