If the front passenger door (not a rear where child locks could be involved) will not open from the inside or the outside, then it is most likely that a cable has come off the handle or lock if there aren't any unusually harsh circumstances involved (like below freezing temperatures possibly freezing the latch).
Unfortunately if this is the case there is little in the way of access to resolve the issue due to the way the panel is removed, the panel is overlapped by the frame of the vehicle making removal with the door closed extremely difficult and almost guaranteed to cause damage.
Given the year, if you are within your warranty mileage I would strongly urge you to get it to a dealership to have the situation rectified. That way there is no risk of expense to you. If you are outside of warranty mileage I would still recommend the same, as they will be more likely to minimize damage having familiarity with the process, plus are possible to identify if there is something unusual/different than expected going on.
If you are set on doing it yourself, there is one screw behind the release handle (small trim panel to remove to access it) and one in the door pull pocket (Again a small trim panel covers it), and that is it for securing bolts. The rest of the panel is held on with pop-in fasteners you just pull to release.... and therein lies the problem with access while the door is closed, there is nowhere really to pull to since it is sandwiched shut. Luckily on this model the top half of the door does not slide down over the door frame like earlier models... meaning you can pop the top loose and work your way down as opposed to older models where you pretty much had to destroy the lower panel folding it to get it to clear the frame. You could try getting the top loose and pulled back enough to examine the cables on the handle and lock; I've seen multiple failures there from the cable not being installed securely (more common on very low mile vehicles since they pop off quickly), the cable physically breaking and the hoop on the handle breaking off, so there are several possibilities there before getting into worse situations (latch frozen, actuator burned up in the "lock" position, etc).