Question
Can you explain to me simply how to trim and care for our knockout roses. Thank you,,, inexperienced at rose care

Answer
When you read or hear about how to prune roses,they are basically talking about hybrid teas or floribunda type roses and that is why it sounds so complicated. However when it comes to shrub roses, and that is what Knock Out is, there is no need for complicated type pruning. You don't even have to prune a shrub rose if you don't want to. The only problem with not pruning, is that the bush could get too large. Knock Out belongs to what they called Landscape Shrubs and these type of roses are planted along highways, in mass plantings in parks etc so you can see they don't require much attention.  
But in a garden you can cut down, to the base, any very thin canes, leaving only the thickest ones, say about 5 canes. Then cut the whole plant back to about 24 inches. Just cut right across the top of the bush. When you prune depends on where you live. if you get very cold winters then do it in the spring if the winters are not very cold then prune in the fall. You can't make a mistake with these landscape type roses, even if you accidentally cut it down to the ground it would still grow back and bloom for you.