www.gardenaction.co.uk has a page on How to Plant a Plum Tree - and bear in mind, Victoria is not a bush, it will be a tree, so you need to plant it where it will have enough room to grow. Basic details are somewhere in sun where the soil isn't waterlogged but doesn't dry out too easily, and somewhere a little sheltered from frosts - plums flower early, so are susceptible to frost damage to the blooms.