Don't worry about fences for at least the first 6 months.
Ground work, "bombproofing" (ie walking over tarps, through things, etc..) and desensitizing are your friends. Get the horse round penning and long lining with very good responses to voice commands. She should also be able to lunge with side reins in all three gaits once a saddle and bridle are introduced. Then the breaking bit, which is about the same for all horses (but be prepared for bigger, stronger bucks!!).
From there it's teaching her to steer from very small commands, teaching her about leg and hand, again with very small commands and getting her broke broke broke and not spooky. Trail riding, going over logs on the trails, etc.
A good ammy horse is a really well broke one that bats an eye at nothing. From that point on, anyone can teach the horse to jump, that is not the hard part.
As far as how she should respond to legs and hand? From very light aids. It is so easy to train sensitivity in babies as they are so sensitive naturally. NO exaggerated hand movements to turn, NO exaggerated leg movements to go and no pulling to stop. If the horse is on good voice aids then adding a small leg, or small hand with the voice aid soon teaches them to go and stop. Turning is very, very easy as well. Reins short to feel the horse's mouth, hands close together and then just turn the horse with a combination of leg and body weight. Don't overthink it! Remember the horse can feel a fly on their flank. They can feel your weight shift, it is then very easy to put an aid to.
If you are ever at all uncomfortable, get a trainer involved. WBs are far less forgiving than a QH and you cannot "scare" them into submission. It is also a good idea to be under the supervision of a more experienced person. And don't touch the jumping unless you are very confident OF. A rider who does not know what they are doing jumping can screw up a horse for jumping for the rest of their lives.
They say money doesn't buy happiness -- well happiness doesn't buy horses!