Newby. You are a fella thinking of joining a woman’s world - indeed a brave chap. I admire your pluck but sadly it is not enough. There are three elements to private horse ownership. Namely the schooling of the horse, the husbandry of the horse and the training of the rider. You by confession have minimal knowledge of horses or riding and that is not a good starting point.
The horse you are thinking of taking on is one which for some reason or another has already acquired a bad reputation but that could be because the so called trainers were not competent to handle a difficult horse - if indeed the horse is difficult. However an unbacked difficult horse is not the sort you need to teach your body how to react and cope with the stresses and strains of riding. In the initial stages of learning to ride, it is the steady plodding dobbin of a horse which teaches your body how to stay mounted. Invariably such horses are to be found in riding schools. You certainly can’t learn to ride without a good tutor and a placid horse You won’t be able to catch and tack up your unschooled horse without guidance. And then there are all the husbandry and horse health issues about which you haven’t a clue.
If you have already got your own facilities including a stable, a tack room, a feed store and a few acres of well fenced grass then by all means consider how to get into horse riding but for sure that wont be with a difficult horse in one hand and a book in the other hand. I’d encourage any young male to consider taking up horse riding but the days of riding bareback and a hand made bosal halter have long gone. Maybe keep the old horse - it can always become a companion horse to a sensible riding horse.
What you need is some help. Go visit the local riding club - if there is one. Buy a few drinks for the locals. Talk about what you want to do and watch their faces. Put an advert in the local newspaper saying: “ Have unbroken horse, need clever rider/trainer - HELP!”
But before you do anything - go find some riding establishment where they will let you sit on a horse and allow you to go round and round in circles for an hour . If when you eventually get off the horse, you can still stand up, then ask yourself if this really is the world you want to join. If it is, then buy immediately a well fitting pukka riding hat with chin strap, an elasticated wide waist and back support, a pair of riding gloves some knee pads and a decent pair of knee high riding boots. Visit a book stop and buy your first “How to ride a horse“ book.
WARNING. A horse can live for 30 years or more. It is a 24/7 365 day a year expensive responsibility - be careful what you wish for, you may get it.