Even when the focus is on the MC, they can still be passive. Beware of verbs like "learns," "decides," "thinks," and of course, "researches" (see Peeve #6: The Research Montage). Be also wary of "must." It may sound strong, but it actually tells me that your MC is a puppet.
None of these is terrible, and I certainly wouldn't command you to banish them from your query forever, but I do recommend caution. Your MC may be the subject of these sentences, but they still aren't being active--all of these verbs can be accomplished while sitting on the sofa in your underwear. What we want to see in a query is what your MC does to accomplish their goal, and that means action.
And if the MC doesn't have a goal to accomplish, you've got a problem.