The Mask of Light has no mind of its own, although it was stated that when it transformed Takua it did impart some knowledge to him that was stored in it. But the mask most likely did no guiding at all; it just lit up when the destined Av-Matoran touched it or willed it to light up, etc.
So, the path is just where Jaller and Takua chose to search for "the seventh Toa". Because Vakama had told them that this Toa "must be found." Isn't that what you'd do?
Oh, and another thing. Is there any particular reason why Takua had to go to Kini-Nui to become Takanuva? Couldn't he just have put on the mask at the beginning and save himself and Jaller the trip?
Not to Kini-Nui to become a Toa, no, but:
1) He had to go on an adventure again to think about things, and come to realize he was destined, and have an experience giving him the courage to put it on. He wouldn't realize it any of this just sitting in a hut (and likely then would have been killed by the Rahkshi anyways; Vakama might have suspected that part at least as part of his reason for urging them to leave, but he also knew Takua was most in touch with who he is when he's adventuring).
2) Kini-Nui does happen to be the way to the Mangaia lair of the Makuta and the Toa of Light was all about defeating him. This much Takua knew, because the Toa had already gone that way and defeated him temporarily (and once the Rahkshi came up, being called "Makuta's sons", it is simple to deduce that Teridax is still alive). Whether Takua delayed accepting his role until he could physically see that location or not (which makes sense psychologically as seeing it has more emotional impact), he didn't technically have to go there to become Toa. As long as he accepted his destiny and put on the mask, he would have transformed anywhere. It was the accepting and getting over his denial that was the hard part.
The real question is whether any of that knowledge stored in the mask could already be imparted to Takua prior to putting on the mask or not -- well, also the extent of what the knowledge was. If so, then Takua's continuing to be in denial about it still could cause them to head away from the Kini-Nui and the mask could, in a sense guide them back there (and he could keep resisting, etc. so ends up wandering for a while). But I don't think it needs to impart anything to him yet for him to realize that he would need to go to Kini-Nui, and delaying until the last moment implies that he'll only transform there (psychologically).
I suspect that knowledge can only be imparted when the mask is worn, too.
But the one answer we can say for sure is no, the mask is not mean, or any other emotion. Basically Takua's irresponsible side to his psychology is what was mean.