Anyone expert here on training horses? What are the warm up exercises that you may want to suggest before getting on with the actual training exercises? Many thanks!:)

There are tons of different exercises you can do to warm up. Most concern starting on a long rein at the walk and stretching in both directions using circles or serpentines or figure eights, then slowly increasing bit contact and progressing up the gaits. it all depends on your horse and what you both are comfortable with and have room to do.