Will this ex race horse be good for a beginer?

the main thing wrong with ex racehorses, that is, any horse that has been raced, is that they are inclined to be nervous and unruly because of the excitement and abrupt violence of the whole racing act. this is true of any animal or person that has been exposed to violent competition. you need a quiet, under Control, pleasure horse just for riding. if you are looking for a horse for some kind of competition it would still rule out an old racehorse. find a horse for what you require of it, a "spoiled" horse is just that and it take a good trainer with lots of time to unspoil one if he, or she, can at all. listen to your mother.