It is very unlikely that you need to move your battery back.

The CG has to be right on the middle of wing tube.

For first flight I would recommend low rates (even 70-80% of low rates as per manual on ailerons) and 30 % expo on everything.

I don’t think it is a good second plane despite that many people here do recommend this plane as second one. It flies not bad and lands itself (but it will not teach you how to lend), you will have to fly it all the time and make small corrections continuously through every maneuver, in particular - in windy conditions.
It is small so don’t fly it too far.

And to find a friend who will trim it for you is a MUST.