As it is pot grown, you can easily leave the plant in its pot for a few days/weeks before planting it. Just ensure you keep it well-watered, and it gets enough sun. Don't leave it for too long, however, as you don't want the roots to become root bound.
The Beech hedge has an average rate of maintenance, and if you are to plan out the care routine, you may only have to prune twice, or even once, a year. The plant can be lightly trimmed in June if necessary, however, we do recommend leaving the pruning stage until the hedge is full established in the late summer. August is generally the perfect time to do so, as the Beech has had enough time to recover and regrow before the arriving winter.
In terms of renovation, this sort of maintenance should preferably be carried out in February, whilst it is still resting. In terms of needing to cut back by more than half the size, it is generally best to gradually do it over two seasons (cut back the top and one side first, then leave the other side for next year). Hard pruning should not be worried about as Beech hedging has quite a fast growth rate, so it will more than likely quickly recover.