Make sure the water supply is turned on. Its located near the bottom of the toilet in the back, turn the handle to the left to allow water flow.

If that doesn't do it then turn off the water supply by turning the silver handle all the way to the right.

The culprit at this point would be the fill-valve. It looks something like this it could vary a bit by model of toilet:




remove the supply line from the bottom of the toilet, if you have a flex point it into a bucket, a hard line put a tray under there and hold your hand around the top of it. Then turn the valve on a second to see if you have pressure.
If you have pressure change the fill valve (fluidmaster). This is the most likely culprit.
If you have no pressure remove the line from the speedy valve and repeat. If this gets you pressure change the supply line to the toilet.