Late summer is cherry pruning time. If you are going to take the whole head off it then I'd wait until late summer next year to get the tree well established with plenty of strong new roots. Don't prune now as you risk the tree getting a bacterial infection which will kill it. My cherry trees are in 50 litre tubs in the garden and I get a fruit harvest from them. They need to be watered and fed. I have also got apples and pears in tubs.