1.5 days over a weekend

Hey guys,

I, Asian male in 40s, going to be in NYC for a business trip and have the weekend (Saturday afternoon through Sunday night) to explore before Monday business-as-usual. I’m coming off a massive long-haul flight on Saturday morning to JFK.

Quick details:
- arriving June second week
- Staying in the Financial District (dropping bags , just one, at hotel first thing Sat). - Is it recommended or could there be a better option so that I could checkin directly at end of the day. I’m sure I can’t checkin before 3 pm
- I’ve already done all the downtown stuff (Wall St, 9/11 center, Brooklyn Bridge, Statue of Liberty) and Times Square on a previous trip, so skipping all of that completely.
- Not a foodie at all. I'll literally just grab whatever quick bite is nearby when I'm hungry. But would still like to taste any must try desserts, coffee, and vegetarian items

I don't have a rigid bucket list, but I definitely want to do:

1. A wander through Central Park. ( Sunday first lake?)
2. A few hours at The Met (Saturday evening?)
3. Some observatory ( Sunday evening? Or could do on a weekday evening as well)
4. Some good budget-friendly shopping or street markets. Open to clothes, local vendors, or just cool areas to browse.
5. Or should I take a full day trip to Niagara Falls?

The options ( dumbo, high line, Chinatown, Brooklyn etc) on web and here are overwhelming, and because of the sheer size of Central Park, met and unfamiliarity with public transport, it’s a bit challenging
Other option is to just rest mostly and just go to mid town lazily if feels like so on Sunday

Appreciate any tips to keep this simple but still making most of it.