My toilet tank is not filling.Any ideas to help would be great

Open the tank and check the black rubber that stops the water. It's the one that will be lift when you're flushing the toilet. See if it needs to be replaced. It might be torn.

If the fill valve in your commode is grey with a blackfloat, more than likely you are going to need to take it apart and replace a small diaphragm that is up in the top, very inexpensive.

Turn off the water valve that is under the tank of the commode, flush the commode to make sure that the water is off, It is going to be hard to tell since your tank will not fill, so be very careful taking the top off.
You take the top off by holding up the float arm and turning the top counter clock wise. You should not see the diaphragm, it has a small hole in the center of it. You can buy these at most hardware stores.

Put the top back on in reverse of how you took it off.

Just a couple questions. Is water coming into tank, but tank doesn't fill? Or is there no water coming into tank at all? Please let us know.

Ensure the shutoff valve (beneath the left side of the tank) is fully open. That line connects to the fill valve which is the likely culprit. Repair or replace it according to your mechanical abilities. If the fill valve is supplying water, the flapper valve might be open or defective allowing the water in the tank to constantly flow into the bowl. This would be visible as a constant swirling of the water in the bowl.

Does your ballcock look lke this? Troubleshooting a Fluidmaster Ballcock (http://www.toiletology.com/troubles.shtml)