My husband and I were in Chernivtsi in September, 2019 - so before COVID and the russian war against Ukraine. We didn’t have much time for sightseeing since we were there for a conference at the university. The university is a UNESCO world heritage site - don’t miss it. I did sneak away for a few hours one afternoon to take a walk on Kobylanska St., a pedestrianized street with beautiful architecture, lots of restaurants, shops. Two restaurants that I remember from that street are Koleso (Колесо)(they put on a great spread for the conference attendees one evening) and Panska Huralnya (Панська Гуральня).
We stayed at Hotel Bukovyna. Somewhat dated - definite tinge of a previous era - though it was being renovated bit by bit when we were there. but it has a delicious breakfast buffet every morning. Make sure to try the banosh (corn porridge) topped with bryndza (a cheese similar to feta) - yum. The buffet included excellent local cheeses. There was a steakhouse next door to the hotel, where we had dinner one night.
If you can manage it, go to Kosiv for the Hutsul market on Saturday morning - it’s not to be missed. But it starts really early - 4 or 5 am, I think.
I’ve been to Kamianets-Podilsky, but it was along time ago - 1993 - one of my aunts lived there. So other than confirming that the fortress is definitely worth visiting I can’t suggest much else.
Not far from Kamianets-Podilsky is Khotyn, there’s another fortress there that’s also worth a visit.