Hi, pretty sure that is a cotoneaster shrub. The flowers will later on develop into very bright red berries, which are pretty in the winter, and the birds tend not to eat them very early, guess they are not their favourites.
You can prune it now , and reduce the number of berries you have, or later in the year, ditto - whenever you do it you are going to lose some flowers or berries. They are very good plants, pruning will really depend upon how much space you want it to occupy.
If it is against a wall you can train it up the wall, it makes quite a nice wall shrub if you want that.