Trip in Latin America this July

Hi all! I (19M) am going to be doing an exchange semester in Mexico city this Aug-December. I’m from Ireland and I want to make the most of my time while I’m there. I’m not sure if I’ll get much time to visit neighbouring/ other latin american countries while I’m there, so i want to take a trip beforehand.

I have three main ideas currently but flight prices keep fluctuating and my mind keeps changing. The first is to fly from dublin to lima in the last week of july and spend 9 days there and then get a flight to cdmx. I’d rather go to cusco and climb machu pichu but i dont have the time or money for that just yet, so I might skip that. The second is to fly to medellin and spend a week there and then take a flight to cdmx. the next idea I have is to fly to guatamala city in the middle of july, spend maybe a week in guatamala before i cross the border into belize, spend some time in belize and then try and make my eay to chetumal in mexico, where I will then get a domestic flight to cdmx. does this sound doable to anyone in a 2 1/2 week span? or am i being optimistic? Does anyone have any better suggestions? All input/advice is welcome!! Thank you!

(sorry for formatting//mobile user)