Does anyone know any sources of how to track down my Navtive Bloodline?

okay so here's what i know. I know that my mom is aztec and my dad's mom is blackfoot inadian. I love everythign about Native Americans and wantt o be with my Native family. But i don['t know much about them and where they are from. Does anyone know of some sources that can help me. Also do you think the MT DNA test is worth taking?