Shutter clicks ever time I press a button & it won't take pictures

First click is to show focus and 2nd click is to capture. its common in most camera's. Nothing to worry about.

Press the DISP button 2 - 3 times & see the result.

This is a common situation with many compact point&shoot cameras. The camera has to do a lot of work between the time you press the shutter release button and it takes the picture; set the focus, meter the light and set the exposure, switch from showing the real-time image on the LCD to capturing and storing a single image, and more. Larger, heavier, and more expensive DSLRs have additional hardware to reduce this "shutter lag" to nothing, compact cameras don't.

There is something you can do to reduce the time, however. If you know where the action is going to happen (a kid getting ready to blow out the candles on a cake, for example), press the shutter release button halfway to focus and meter. Hold the button there until the action happens, then press it the rest of the way. This lets the camera get most of the work done before taking the picture.

This is a common situation with compact point&shoot cameras. Between the time you press the shutter release button and it takes a picture, it has a lot to do. It has to find the subject and focus on it, meter the light and set the exposure, perhaps set the white balance, and other things. Larger, more powerful (and more expensive) DSLRs have more powerful processors and additional hardware to speed up the process.

One way you can reduce this shutter lag is to press the shutter release button halfway to focus and meter before you need the picture. Keep the shutter button pressed halfway until the action hits its peak, then press it the rest of the way.

This is a common situation with compact point&shoot cameras. Between the time you press the shutter release button and it takes a picture, it has a lot to do. It has to find the subject and focus on it, meter the light and set the exposure, perhaps set the white balance, and other things. Larger, more powerful (and more expensive) DSLRs have more powerful processors and additional hardware to speed up the process.

One way you can reduce this shutter lag is to press the shutter release button halfway to focus and meter before you need the picture. Keep the shutter button pressed halfway until the action hits its peak, then press it the rest of the way.

The only way is copy pictuers from internal memory to the external memory using the camera Copy pictures or videos:
1 Press the Review button, then press the Menu button.
2 Press to highlight Copy , then press the OK button.
3 Press to highlight an option:
PICTURE or VIDEO-copies the current picture or video.
EXIT-returns to the Review menu.
ALL-copies all pictures and videos from your selected storage location to the
other location.
4 Press the OK button.

NOTE: Pictures and videos are copied, not moved. To remove pictures and videos from the original location
after copying, delete them

You say in your description that you're "focused in". That means that you've pressed the shutter button half-way and allowed the camera to lock in the focus (it will beep). You need to maintain that half-press until the moment you want to snap the picture and then press the rest of the way. That will give you a faster, "instant" picture. Is that what you do?

Putting Yourself in the Picture The Self Timer creates a 10-second delay between the time you press the Shutter button and the time the picture is taken. 1 Place the camera on a flat surface or use a tripod. 2 In any Still mode, press the Self Timer button. The Self Timer icon appears in the status area. 3 Compose the scene. Then press the Shutter button half-way and hold to set the exposure and focus, then press the rest of the way down. Move so that you are in the scene. The Self Timer light blinks slowly for 8 seconds (then quickly for 2 seconds) before the picture is taken. The camera "clicks" when the picture is captured. To turn off the shutter sound, see page 64. The Self Timer turns off after you take the picture or if you change modes. To cancel the Self Timer before the picture is taken, press the Self Timer button. (The Self Timer setting remains active.) To turn off the Self Timer, press the Self Timer button twice.

[source]Question about Samsung Digimax S500 Digital Camera[/source]
Try replacing batteries (high Ah photographic type).
The lens motor & electronics may be draining power if Ah capacity has dropped too low. At night, it could be that your flash is trying to fire (another drain), or shutter timer / mirror staying open longer.

Are you sure you did not activate "Manual Focus"?
Near the shutter button, there's a "Focus" button. maybe you pressed it accidentally and now you're in "Manual Focus" mode.

If so, press it once more to get "Multipoint" mode back to life...

And read the camera manual. It's a goot place to look for this kind of answers.