You can choose a character with "no attachments" for this event. That character will still gain renown, but the second part will not resolve, so the event will be placed in the discard pile.
If you are playing A Mummer's Farce, the Forced Reaction on the agenda will trigger for any character that has "Florian and Jonquil" attached, and you will be able to marshal or play those cards. Note that "Florian and Jonquil" does not become a facedown attachment itself though, so you cannot play it again in that scenario.
If the character already had renown, the pre-then part of the effect is still considered to have resolved successfully, so the event will still enter play as an attachment. Same if the character fails to gain a functional instance of renown (due to having a "negative value" of renown beforehand).