Call a locksmith.
you have a few possibilities. the linkage could be disconnected on the handle, you could have broken linkage from the handle to the latch or your lock linkage could be disconnected while it is in the lock position. all of these can be accessed from the interior door trim panel. to get the door open you will probably have to remove the interior screws while the door is closed and pull back the panel as far as you can. be careful not to break it but you should be able to reach the linkage and open the door from inside the door frame
if its a lift up handle and wont open your door most probably the rods come out of its slot inside the door
how to open liftgate on 98 lincoln navigator that is stuck
If I understand the question correctly - - the door is on child safety lock and you can't open the door to fix the handle. If so - - you will have to remove the interior door panel to gain access to the locking mechanism and unlock it manually. Mechanical methods of opening the door (Slim Jim's, etc) stand a good chance of damaging the locking mechanism by forcing it, and you (or someone) will have to remove the door panel to repair it anyway.
You have to pull the inside door panel off. Once removed, look for the door latch mechanism and pry it with a screwdriver. This will release the door.
The plastic on the inner handle has broke. One of the plastic gears just replace the actual handle (hard to find) get at a junk yard.
I suspect the rod that opens the door has come loose or broken off the door handle and is keeping the window from coming down. Take the inside door panel off and check. If needed just replace the door handle.
Take inner door panel off and look inside the door and you will probably find a rod off the outside door handle.
Typically there is a series of rods on the inside of the door which converge near the handle to connect the inner and outer handles along with the lock. The plastic connector from the handle to the rod may be broken. Try taking the door panel off and inspecting the area.
Go in from another door and open it from the inside.
Use the key to open the door.