Ok I'm leaving for mexico asap, where do i go!

[dallas101soldier]

I have just broken up with my girlfriend and thrown this trip together in the last couple of days. I bought a ticket to mexico city and plan to just go ever where the wind takes me for 2 weeks, while trying to make my way back to el paso texas in the end. I have no idea what to do or where to go. I bought a recomended backpack and plan to stay in hostels the whole time. I am trying to do this for as cheap as possible, but i am fexible if there is something fun to do. really just want to see the country meet fellow backpackers and drink. My questions is what should i make sure and see or what is cool that i can't miss, where should I go? any tips on any bad spots to watch out for? What not to do? Any other tips of things i need to bring or don't need to bring? I thought about bringing a sleeping bag for the hostels do i need too? help me please, oh and everyone is telling me that i am going to get robbed and stuff, is that true. I have read some that says it is and some that says it isn't. Is there usually hostels in small towns? please post thanks tommy.