Lorn? Check out the spelling of that word. It could be a name but it's not an English word that we use these days.
Upon. Yes, this is a word. I sat upon the chair = I sat ON the chair.
You'll meet the word in novels and poetry, and in some expressions. "Once upon a time there was a princess and a frog...... " Really you can simply take the 'upon a time' out of the sentence. Once there was a princess and a frog..... "
As SuKi says, you won't need to use this word much at all, but you will meet it sometimes.