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.
This is probably the best way to choose a breed of horse. As many breeds of horses may be interpreted differently by many different views. My friend had a Palomino and it was crazy or My sister had an Appaloosa and it was ugly. Different people have different views so it is best to try it for yourself.