Ill be catching a flight from Tijuana to Mexico City. Can I travel with my US passport or will I need to get a Mexican passport?
You can't get a Mexican passport unless you are Mexican citizen.
Generally speaking, for travel you need a government issued identification document with your photo - a passport any passport qualifies for this.
Depending on the flight, you may also provide other forms of identification in lieu of the passport (for example, a driver's license is accepted on most domestic flights in the US - even from non-citizens).
In fact, depending on the circumstances - the document doesn't even need to be valid/current (for example, if you are trying to prove your right to enter by citizenship, an expired passport will suffice).
depends, usually they do not ask you for one if it has your picture if you are travel withing México, because they have no way to prove you are mexican, so as long it has your picture, you can travel with it without problem