Sakura tree

Hello all, I have just received a sakura ( Yoshino cherry blossom) tree, about 6 or 7 inches tall, in the mail. It arrived with leaves and appears healthy. I mean to let it grow until it is about 1 foot and half to 2 feet in height, before I transport it to the ground. What do I need to do to care for it in the meantime, (when can I transfer to a bigger pot?) and is my plan ok? Fertilizer? Can I…