Museum of Frida Kahla is in the house she shared with Diego Rivera for many years. Gives you a run down of her life. You need buy tickets ahead of time, there are no in person ticket sales. Buy tickets here https://www.boletosfridakahlo.org/
This is the center square of Mexico city, great to walk around and enjoy some of the surrounding museums and food options. Check out this write out to see what to do around the surrounding area https://www.cntraveler.com/gallery/best-things-to-do-in-zocalo-mexico-city
These are impressive and mysterious pyramids that predated the Aztecs. The pyramids are about an from Mexico City, and you can spend up to 2 hours exploring the many landscapes. You can also do the hot air balloons and see the pyramids during the sunrise.
Wander through the vast park with walking, running and biking trails, a zoo and several museums. Guide to Chapultepec https://travelmexicosolo.com/things-to-do-in-chapultepec-park-mexico-city/
The Food experience you can have in Mexico City is top-notch. Bang for your buck there are few places like it. Here are some places to check out Botanico (beautiful outdoor space) Lardo (Mediterranean) Rosetta (Italian) Maximo Bistro (Italian/French) Fugaz (Tacos) Orinoco (Tacos) Contramar (Seafood) Madre Cafe (Brunch) Ticuchi (Mexican) Niddo (Breakfast) Masala y Maiz (Fusion Mexican & Indian)