Random things in my document

I recently had a random N show up at the end of a line in an Illustrator document that defied my efforts to remove it. I finally put the word on the next line and it disappeared. I had to change the length of all the lines to match. And today I made a set of .png proofs that showed the little red plus sign indicating there was additional text--but it was showing in the printed copy. Those are supposed to be invisible guides for me. Not for my client. Totally weird. I am on a mac 15.3.1 Sequoia, using Illustrator. I have installed updates.