This question is far to broad and general to be able to answer it. It will take a very lengthy explanation for this sort of question, and even so how to train a horse differs between each trainer and each individual horse.
Its not a horse its a train
Yu train a Morgan horse like any other horse
To train your horse you have to press the little plus sign beside the bar that you'd like to train them in.
Just do lots of practise.
Train it.
by grain
no.
you should train a trotting horse at the age of 5 years old.
you kick the side of the horse and get it use to that
An Iron horse is a metaphor for train locomotive
Probably the horse drawn wagon train
it depends on who you want to train and/or break your horse.