It will feel like some one is pushing on your teeth. The brackets stick out a bit from your teeth making it feel like you have a full mouth of metal, big lips and your bracket may rub against your lips feeling again like a metal file.
While some breeds may be more suitable than others for a beginner rider, there are always exceptions to the rule. Quarter Horses often make great beginner horses because of their even temperament, but some can be quite hot or energetic for a beginner.
So there is no right or wrong breed for a beginner. The individual temperament of the horse and its training are more important than its pedigree. Many new owners like draft crosses and draft breeds. These horses often have a quiet demeanor that beginners, and some older riders enjoy.