How to set shutter speed on a nikon d5100?

So i wanna do some light grafitti with my nikon d5100. I know how to do everything BUT set the actual speed. If i try to take a picture it takes like one picture and doesn't give me time to do ANYTHING. HOW DO I FIX THIS!

If you read your user manual, you can see how you can set the shutter speed to bulb.

If YOU are going to make the graffiti, then need a remote shutter release

Place the camera on a tripod.

In the manual focus mode, pre-focus the lens to where you will be.

Lock the shutter open and do some tests using different lens aperture until you get the one that produces the best colour saturation.

Take the dang camera out of full-auto. Have you read your manual yet?

Manual, manual focus set to infinity, ISO 100, f/8 or so, 2 second self-timer. Sstart out with a 2 second exposure. If thats too long, then use a shorter exposure, if it too short use a longer exposure.

Set your camera to manual mode and set the shutter speed and aperture you want (see page 65 & 66 in your manual). You may need to set your camera to manual focus mode (see page 45 in your manual).
This will give you a maximum of 30 seconds to do your graffiti. If you need more time, use Bulb mode. You'll need a remote or have someone hold the shutter release button for you.

Well what you want to do is try to set it at the longest shutter speed without over exposing the picture. You have to learn about the holy trinity of photography "shutter, iso and aperture".

First you need to need to set it to manual mode.

Set shutter speed to the amount of time you need (10-30 seconds).
Set aperature to f8-f11 to stop light from getting in.
Set iso to 100.

Your settings may vary, but it should guide you to your results.

Do you still have your Owners Manual? If so than why haven't you Picked Up and Started Reading your Owners Manual because the Owners Manual covers so much of the Basic Camera Operations including on How to change the Shutter Speed.

It depends in the mode you are in.
1.M mode or manual mode: just simply turn the control dial just right above the rubber nipple. You can set it from 1/4000 to 30" and bulb.
2.A mode: no hope. The camera chooses the shutter speed.
3.S mode: just the same as the M mode
4.P mode: no hope. It has preset settings for you to choose from.
and lastly,
5.A mode: seriously who the *** uses that mode?
if you really don't know how to read the users manual or google it or go to photography school.