I grew up in SF and moved to NY 18 years ago and have never regretted it. It's an amazing place to live and I have every intention of living here for the rest of my life.
But coming from Texas, you're going to experience culture shock.
We are not terribly friendly. In TX the cashier at the supermarket will engage you and have a conversation. The only conversation the cashier in NY will be having is with the cashier next to her. You're more of an inconvenience to her than a valued customer. Strangely enough, in a short period of time this will not bother you.
Speaking of supermarkets, get used to buying your groceries in tiny, crowded stores with high prices and terrible selection. Seriously consider having your groceries delivered. Many people never turn on their oven, using it instead to store pots and pans, or in some cases, shoes.
Your neighbors will not be friendly. When I first moved here I would have pleasant small talk with my neighbors while in the elevator, walking the dog, etc. Nowadays everybody has their face in their phone. Get used to being ignored, even by the building staff, except during the months preceding Christmas. Then they're your best friend.
If you think it would be fun to (fill in the blank) be prepared for the fact that 10,000 other people have the same idea and got there ahead of you. I got turned away from a 1940s film noir from Spain at MoMA because it was sold out...at 5 in the afternoon... on a Thursday.
Commuting on the subway is utter hell. In the summer, you'll learn to stay away from an empty subway car. At best, it's un-air conditioned. At worst, there's a homeless person who has made the air unbreathable...or a pile of vomit...or a body.
But I would commute a hundred years on the subway rather than do one month on the Central Expressway.
Broadway has sold its soul to the tourist trade, as has much of the city. They're everywhere, like roaches, travel in packs, and walk five abreast, slowly, whenever you're trying to get somewhere.
On the plus side, when friends realize you have no spare bedroom and that they'll have to sleep on the couch, their visits will be short...or they'll stay in a hotel...or stay home.