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.
If a beginner has to choose between a stallion and a gelding, the gelding is by far the safer and wiser choice. Besides making a safer, quieter and more well-behaved riding horse, gelding serves as an effective way to avoid unwanted offspring and ensure that only the best horses are kept for breeding purposes.