*Yep, never assume. His father even had rhyme about assuming. He wasn't going to say it here though, it had a bad word in it and the headmistress already looked mad. No need to poke the bear.
Protection spells? He was still only a first year, so not many dueling and protection spells. Now if it came to protecting himself the muggle way then he had a whole list of ways to protect himself. But for now...*
"Protego, Miss. That's a spell that will help keep you protected."