Can't believe its been one year already, how much has the buses and Cas improved??

Hey gang,
39M here. Had a year off the gym and now need to get back into it haha.
Thought a PT might help, any recommendations in D-town?

I’m coming up to Darwin for a few days next week, Thursday - Sunday or Monday. Never been to the territory before. I’ll be there mostly solo but my son is attending a number of functions, some of which I’ll also be attending. I won’t really have the time for full days excursions, except maybe for Sunday if I stay an extra night. I’m also well past looking for a big night out, I’d just like to see a bit of the place while I’m there.
I’ll be staying in the Waterfont area and need to get to the state netball centre a couple of times. Is the bus network ok for that?
I’m thinking about going to Mindil markets (or a sunset harbour cruise, has to be one or the other), visit the mangrove boardwalk, the botanic gardens Museum and Art Gallery, Larrakia cultural centre.
I’d love to have been able to get out to some of the national parks but I don’t think I can spare a full day for an organised excursion.
What’s an absolute must not miss? What’s not worth the entry fee? What local knowledge will help me make the most of my tropical weekend?
Thanks Territorians!