No water in toilet

Shut off valve is closed. If not that and the toilet fill valve is the type that has a float the moves up and down on a shaft, you need to replace the washer in the top of the fill valve. Shut the water off, hold the stem of the valve and turn the head of the valve 1/8 turn counter clockwise. The washer is under the head, it is about the size of a quarter, black with a small rod sticking out of the center.

Some fill valves have a float on the side that pivots on top of the stem to shut the water off. There is a cover over the head, then remove the float and turn the top of the valve. Same type of washer underneath.