Planning a trip to Mexico, and Mexico City in general is overwhelming. Everyone has an opinion on this beautiful location. Rest assured that no matter what you choose to do or where you choose to stay you'll have a beautiful time.
One last thing... even though researching ahead of time is great, I definitely recommend bringing a Mexico travel guide along with you. Here are some books I recommend...
And of course, if you have any questions DO NOT hesitate to reach out to me via Instagram, Twitter, or just shoot me an email (firstname.lastname@example.org).