ok how do i charge or inflate my air suspention on my 2000 ford expedition 4x4 all wheel drive front and rear air

if it's a factory air suspension, the leveling pump fills it.
you'll have to check fuse, air lines and sensing lever.
if all that checks out ok, you'll need to check wiring and componets for correct power and grounds.

Once you've checked the fuses and relays, if they are OK; try this:

locate the air pump (leveling pump) underneathe the vehicle.
Start the engine.
After a few seconds the pump should turn on.
Slide under the vehicle to see if the pump is working.
If not, check for power (using a test light) at the pump's wiring connector. Also check for the ground wire to be sure it's getting a good ground.
Also check the leveling arm which is a short piece of metal which connects to the vehicle frame and to the air pump control mechanism (as the frame sinks lower from the load in the vehicle the arm pushes on the switch which in turn, turns the pump on).

If the pump does run, use a spray bottle with soapy water to check for leaks at the line connections and air bags themselves.

also check the air suspension switch located on pass side kick panel and make sure it is in on position. should be turned off anytime vehicle is lifted