As it is pot grown, you can easily leave the plant in its pot for a few days or weeks before planting it. Just ensure you keep the plant well watered and it gets enough sun. Don't leave it for too long, however, as you don't want the roots becoming root bound.
Copper Beech is quite a low-maintenance plant, and if you look after it properly, it should only need a prune once/twice a year. You can tidy the plant up in June, but we highly recommend sticking to trimming your Beech in late Summer- i.e., August. This will give the hedge enough time to recover and re-grow before Winter.
You can easily hard prune Copper Beech as it has a relatively fast growth rate and can quickly recover itself.