It sounds like an amazing trip! I suggest you buy a guidebook for Sicily and thumb through it to see if anything in particular calls out to you, and see if it makes sense to work that in. I was a fan of the Montelbano TV series during Covid lockdown, so I was longing to see the Baroque hill towns featured in the series, and I based myself primarily in Ragusa Ibla for my first (solo) trip, essentially just hanging out, taking strolls around town, sitting in the town garden to read my novel, enjoying a light lunch and an aperitivo and dinner in the evening. I spent 2 days seeing the other hill towns, then a couple of nights in Ortega and 2 nights in Catania to be close to the airport for my return flight. I felt like I was in heaven in Ragusa Ibla, but I didn't try to run around to see everything possible, and dropped almost everything that I had on my original itinerary. I saw much more of Sicily in my subsequent trips and discovered how much I love Palermo. (I have been twice for the Easter processions, and did a two week language class in Milazzo, a few days in Palermo, Good Friday procession in Trapani, and a week long bike tour on my last trip.)
Be aware that train travel is not as efficient in parts of Sicily as is in many other parts of Italy. Sometimes the bus is a better option between towns. There is a person (Vagabonda) on the TripAdvisor Sicily forum who is a great resource for links to timetables for local bus service if you have specific questions.