Calculate the price of your horse's idle time in advance. It will include stall rent, food, grooms, veterinarian and horseman services. When choosing a stable, pay attention to the condition of living of other animals, how clean, well-groomed and well-fed they are. Most likely, your horse will be treated the same way.
To build relationships with your new horse and make friends, spend as much time together as possible. Come to it at least four times a week, devote it a weekend, take care of it yourself - cleanse, saddle, harness. After walks, if it is not winter time, wash your horse. All this will help you become true friends! If you are not ready to devote so much time to a horse, perhaps you should abandon its purchase and just occasionally enjoy yourself horseback riding at the rent office.