You also appear to have a solid axle, not a QR with skewer.
Nothing is missing (apart from possibly some ball bearings) assuming you have the wheel nuts.
So, on the non drive side, where your cone is wayyy out of place and showing the bearings, you need to find out why. It is possible (but not likely) the threads are stripped, either on the axle, or in the cone. Also you need to see if any bearings (or balls if you prefer) are missing. With the cone that far out, some may have fallen out.
I'd undo the locknut and cone on the non drive side, withdraw the axle from the drive side and examine the axles threads. No need at this stage (or probably at all) to undo the locknut and cone on the drive side (although it is possible its that side that may have stripped threads, still unlikely but possible)
As RAFN says, examine the cones and balls...but TBF I have re-assembled hubs with doggy bearings as a keep you going thing.
Clean all the components, cups in the hubs as well, smear plenty of grease in the cups, lay the balls in the grease to hold them, then slide in the axle, spin on the cone to roughly the right place, spin on the locknut to the cone, then you start fine adjusting.
It is a practice thing, as you find a sweet spot with the cone, you lock up the locknut to the cone, but if the axle moves, it throws it all out again. Adjust, lock, check, adjust, lock, check till its just right.
