Visiting soon. What are some must see & do things?

I am accompanying my partner who has a work conference in St. John's at the end of April for 5 days. I will have a lot of free time during the day while he's in meetings, and I'll possibly have a rental vehicle. We'll have time together in the evenings to explore. We've never been to NL and we're both super excited to get there, but I want to check in to see what folks recommend. I obviously want to do and see as much of the tourist things as I/we can, but I'd love to get to know St. John's and see more than the tourist websites offer. Thanks in advance for your time!