If you have flushed to much toilet paper down the toilet or if there is something else clogging up the toilet bowl then what you have is called a stoppage. Most toilet stoppages can be cleared with a hand snake or even a plunger. It all depends on how much of what was flushed down the toilet. If you were to flush something like cat liter down the toilet and it was the clumping kind of liter then you might not be able to unstop that from your toilet bowl with just a plunger, you will need something more like a toilet auger. If you have accidentally just used to much toilet paper then most of the time the plunger will in fact unclog the toilet bowl trap.
If the object that you have flushed down the toilet made it through the toilet trap it could have possibly now made it into the main sewer line and you will need a bigger snake to clear the main line. The first thing you will want do to try to unclear your toilet stoppage is to plunge the toilet. You can plunge the toilet by taking the plunger and placing it over the whole in the bottom of the inside of the toilet bowl. You then will want to push up and down in a forceful motion around 5 – 10 times. If you see the water level inside of the bowl go down the drain you have successfully cleared the stoppage that was in your toilet. If the water level is still the same you will want to try this process a few times. If the plunger is not working you will want to try the toilet closet auger next.
The toilet bowl auger is a tool with a metal wire snake that can be forced to clear the stoppage inside of your toilet bowl trap. The auger has a handle on it that you you will turn and as you do the metal snake will wind itself through the stoppage in the trap. Once you have spun the auger snake all the way into the trap you will want to extract it by spinning the handle counter clockwise and then the water in the toilet bowl should go down. After using the closet auger try flushing the toilet. If your toilet bowl is still clogged then you will have to remove the toilet bowl and either manually clear the stoppage or try a longer snake to clear the stoppage. You could alternatively hire a plumber or drain cleaning company to clear the stoppage out of the line for you. Many plumbers these days even have digital cameras on the end of their snakes so they can see exactly what is stuck inside of their sewer line.