Hey sweetie! See if this site helps:
Pruning Clematis's

* * * *

Hmm... that might depend on how sturdy your arbor is. Roses can become very heavy and need good support. The kinds of clematis that like being severely pruned each year are probably lighter in weight and suitable for a more delicate arbor or trellis.

I have a Jackmanii clematis that my husband regularly prunes to the ground by accident with the weed wacker in early spring. Even though it gets cut to the ground, it manages to very rapidly grow back to it's former height and beyond by summer.

You may have to be patient while you wait for a clematis to mature enough to blossom. If you get a bare-root plant, it can take a few years. If you want blossoms sooner you might choose a climbing rose, instead. In either case, you'll have to tie the vine to the intended arbor until it figures out what it's supposed to climb.

* * * *