How do I get the tank on the toilet to refill on its own?

the toilet used to run after flushing, my house guest turned off the water instead of lifting the stick or jiggling the handle. Now the tank won't refill on its own. I've turned the water back on, I've made sure that everything is in working order but either the toilet won't flush or I have to refill the tank manually. I'm renting and don't want to have to call(and pay for) a plumber because my landlord knew that the toilet continued to run when I moved in here but didn't have it fixed just told me how to, temporarily, fix it when it happens. Please help

Sometimes the rubber washer in the angle valve (on pipe coming out of wall or floor) falls off from age and corrosion and blocks the water from feeding into the tank. Turn valve counter clockwise to open. If you feel a grinding sensation your valve is probably shot. If you can shut the valve off, you can then look in the toilet tank and see the fill valve. If this fill valve says FluidMaster on it you can take the top of the valve off to get to the rubber washer in the fill valve. ONLY IF YOU KNOW THE WATER IS OFF.... Sometimes dirt clogs the washer. If you are not handy with home repairs don't do this.
Ask the landlord to try. If he floods the place your not at fault.
If the toilet runs and you have to jiggle the handle to make it stop the flapper is probably bad. It is connected to the handle by a chain. There are several types. Some clip on the overflow tube , some are on the bottom of a barrel type float.
Your local plumbing supplier can help you. Go there with the manufacturers name of the fixture. American Standard, Kohler, Gerber etc... Local Plumbing Suppliers sell Toilet Rebuilding Kits in a box. Fluidmaster makes them. Fill Valve, Flapper, Handle, etc... Cheap, with Instructions. Your best bet is to ask the owner to do this, be nice it works better than threats........

Call a plumber, and hand your landlord the bill. If need be, get an attorney to explain it to both of them. The landlord has a legal obligation to keep all equipment in working order; and he has admitted the toilet was not working properly when you moved in.

You may not have turned the valve back on. The valve should be turned counter clockwise to turn it on. Before you do this you might put a drop of oil on the shaft of the shut off valve to make it move freely. Good luck.

check the isolator near the pipework,see if it was turned off,its a little silver connector in the pipework with a flat head screw