Certified GKH Gardening Expert
There are too many clematis cultivars to recognize the foliage; many look the same. It helps to know when it blooms and a picture of the bloom. If it has small, white flowers and blooms in late summer it could be Autumn clematis, which is very aggressive, and if the seed heads aren't cut back, it will come up all over the yard. Since there are different pruning types, you risk losing this year's flowers if it is pruned at the wrong time. So, I would just lightly prune it now, then after it blooms, you can give it a more severe cut.
Here are the pruning types: