How does a pilot start the engine of an air force aircraft? Does he insert a key like a car?

Many small single engine aircraft have keys, although the starting procedure is a little different than starting your car!

a set of togel switches. One for the main power. one for the ignition one thatspins the engin and one that turns on the fule. boom bang and fire comes out the rear. Now all you got to do is learn to fly.

Jim is most correct, in regards to fighter aircraft, except I think he forgot that the F16 does also use a JFS, which is spun up to starting speeds itself by hydraulic fluid stored under pressure. The F/A 22 does have an APU installed in the left side of the fuselage/wing root area, it is used for bleed air start of the engines/ground use of the AC systems and powers a hydraulic pump and small generator for ground maintenance use/emergency use in the air.

He looks at it and says... "Oh mama turn on so we can fly"

Basically, starting an aircraft is different from starting a car. If an aircarft is started in the same way as a car does, it will explode. Aircraft fuel is more flammable than petrol.

No there are no keys. But the starting technique does depend on the jet. Some require the use of an APU (auxiliary power unit) to start the engines turning and then they fire up on their own. Most use an electric start (just a switch) and when the engin reaches a certian RPM and temp they press an ignition button that sparks fuel in the engine and starts the combustion and then the engin runs on its own.

Not that I have ever started one but, imagine the pilot going "Now where did I put those keys?" My guess is that they start much like a Fire engine in that you engage the battery power and start the engine through the use of a few switches or knobs. Just a guess though.