pruning climbing roses

I wouldn't prune a 1 year old climbing rose at all, only exception would be to cut out diseased or rubbing branches.
I think it is more important this year to train your branches, bending them to cover the area and towards the horizontal where possible, to encourage flowering shoot growth. Tie them in where you want them to stay

As Momofstig says, don't prune it yet as it is too young and needs to develop a framework to prevent all the flowers being produced at the top of the plant. You have to bend the new sappy canes gradually, i.e. in stages, to as near horizontal as you can - about 10-30 degree angle - as they grow. This means that the stems from these canes will produce flowers low down from shoots along the canes. These shoots (not the stems) you cut back to one or two buds at the end of the season. Depending on how many new canes you get, tie in some at a lesser angle to achieve a fan shape. If the lenght of your canes outgrow their allotted space, just cut off their tips. In time, your original canes may need to be cut down somewhat so as to produce new canes lower down. Someone on here more experienced than I will telll you.