'94 ford explorer, when I start car, I need to turn keys a second time for it to turn over, I changed spark plugs (new cables also) new gas filter and still it takes two turns of keys to turn on, does anyone have any suggestions?:o :o :o

Here's how I start my cars. First, I turn the ignition switch to ON and wait for the CEL to go off and the fuel pump in the gas tank to stop running. This fully pressurizes the fuel rail. Then, I turn the ignition switch to START and the car fires right off. This approach is easier on the battery and starter motor. Fully pressurizing the fuel rail, first, particularly helps cold weather starting.

If the problem continues, you might want to check the ignition switch--there could be wear or pitting.

Is it not turning over the first time or is it not starting? There's a difference between the two. If it turns over but doesn't start, you may have a weak fuel pump. If it doesn't do anything, then like tx said, it could be the ignition switch.

'94 ford explorer, when I start car, I need to turn keys a second time for it to turn over, I changed spark plugs (new cables also) new gas filter and still it takes two turns of keys to turn on, does anyone have any suggestions?:o :o :o
That actually sounds to me like there is a problem getting full power to the starter.
Make certain that both ends of both battery cables are clean and tight, free from corrosion.
You may have a faulty starter motor, or simply a weak battery. Have these tested. You've already eliminated the secondary ignition system.