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.
Your first horse should be older, calm and well trained in at least the basics, with no bad habits or vices. Around here, you can find horses like for $250 - $1,000 (or more, if you have lots of $$ - I don't), depending on what their breed (and sadly, color) is.