I can't advise you on pruning or espalier technique but I can say that is a large fig tree. Do you know what variety it is? That information along with what zone you are in might help others help you.

Yes, you can espalier figs, I've seen a few photos. They're pretty tough, so you can prune them pretty much as you like. Depending on the variety, you may lose the early Breba crop if you prune, but many people do not care for that one anyways. Main crop fruit comes from new wood produced that year. So once you get the basic espalier shape, prune each fall/winter to maintain the shape and size you need.