@Kaihaia0 I agree with all of @Emilia42's advice there.
If you have friends living in Mexico City, I would definitely recommend getting their advice about neighborhoods and transport, supplementing with some of your own research, looking around on Google Street View at the places that get your attention. When you're searching for listings you can narrow the search down to a specific area of the city map, and you can also filter for features such as the key amenities most important to you. If you'd like to ask some questions before committing to a booking, click "Contact Host" just below the main description to send a non-binding inquiry.
For most host, the ideal guest is one who reads the full listing, House Rules, and cancellation policy before sending a request or Instant Book - it's a common pet peeve to ask for info that's already covered in the text, or request additional services (such as a private viewing) that aren't explicitly on offer. If you're traveling during a time without a lot of tourists in town you might luck out on a last-minute opening once you're already there, but you have far more options if you book at least a couple weeks before your trip.
Also, be aware that many hosts require you to have completed the ID Verification process in order to book, so for best results I'd suggest completing your verifications first. And if you don't feel like writing a blurb about yourself in the profile text, it helps to communicate a little bit about yourself in the request message - why you chose the listing, plans for your trip, scheduled arrival time etc.