Sorry to be a downer but if it were me I wouldn't perform Odyssey right away especially if you're known to not wear rings... I would get people used to the fact that I wear a ring, also I would do ring magic, for a while, using other people's rings way before ever trying Odyssey
A) If I am walking around or sitting down with a ring, I am clearly wearing it.
B) I will switch it out for a real one at the end, so it doesn't even matter
C) I have been wearing one for a while, so most of my close friends know about it.
D) It's the first day of school. No one is going to remember who wears what. Hell, people will forget other people's names.
E) I am going to present it as if it were done impromptu
F) No one is looking at my hands long enough to know if I wear a ring normally.