Unless you have YEARS of deaing with insecure and unbroke horses under the supervision of a trainer - RUN do not walk, but RUN away from this sort of horse as a first horse.
There are thousands of great horses who need homes who won't be potentially dangerous to a new horse owner - many of whom will end of dog food.
PLEASE consider a different horse.
The last time I watched a new horse owner get a horse it was a disaster. The girl was 12 or 14 somewhere in there. She had two months volunteer experience at a horse rescue. Someone at the resuce advised her to buy this mare who had unknown training and had been sitting for 2 years.
To make a long story short, everyone at the boarding stable told this mom that the horse would end up killing this girl. The horse had great training, but was too sensitive for any but the best of riders. The stable ended up asking them to leave, as no one wanted to watch the kid die - she hit the ground five times in the first month alone - and never left the round pen!
At the new stable they went to, someone decided to punich this very sensitive horse by tying her nose to the stirrup and chasing her around with a whip - the horse was terried and ran into a wall - snappingn her neck and dying within the hour.
I am sorry to be so blunt, but please consider a different horse.