Is there any difference between an "Assistant Professor" position and "Assistant Teaching Professor"?
"Assistant Teaching Professor" isn't a very common title, and the meaning of the title could vary from one institution to another. However, I would assume that an "assistant teaching professor" was a position for someone whose responsibilities included only teaching and perhaps some service but no research. In that case, it would most likely not be a tenure track position.
The two important factors here are whether the position has both teaching and research responsibilities and whether or not it's a tenure track position.