If it will not focus even in bright daylight at the wide end with a single focus point and no macro or face detection and that is almost certainly hardware. If you can swap lenses, do that to confirm whether it is the lens or the body. Fixed lens models that have seen sand often end up with a jam and you might hear a faint buzz when it hunts. Repairs take weeks and you have a trip coming up so even if you send it now you might not get it back in time, and the bill can be a big chunk of what the camera is worth. I actually would borrow a camera if possible or use manual focus as a stopgap for the trip, then decide on repair after you are back.
