First solo female trip to NYC, looking for local advice

I’m visiting Manhattan solo this October and I’ll be staying for about 20 days in Murray Hill. I’ve traveled to several European countries before, but this will be my first time in the US.
Visiting New York has honestly been my biggest dream since I was a kid, so I’m incredibly excited (and maybe just a tiny bit nervous 😅). I have a few questions for people who live in NYC or know the city well.

This will be my first solo trip. I know Manhattan isn’t some crime-free fantasy, but I’m not overly worried either. I’d just love to hear your advice.
I’d really like to explore the city after dark too. Is that generally okay? Are there any areas, situations, or common scams I should avoid? Any safety tips you’d give to a first-time solo traveler?

I already have most of the famous tourist attractions on my list, so I’m much more interested in local favorites.
I’d love recommendations for:
hidden gems
neighborhoods worth wandering around
restaurants, bakeries, coffee shops, and street food
parks or peaceful places
bookstores or other unique spots
Also, where are your favorite places to watch the sunset or enjoy the Manhattan skyline?

Since Halloween isn’t really celebrated where I’m from, I actually planned my trip around that time on purpose.
Are there any Halloween events, neighborhoods, or seasonal activities that you think are absolutely worth experiencing? And is there anything else that’s a must-do in NYC during October?

I’m planning to see several Broadway shows. Are there any that you personally wouldn’t recommend, or any hidden gems that deserve more attention?
I’d really appreciate any tips, recommendations, or things you wish you’d known before your first visit.