That clump of toilet paper probably didn't go very far. For about $30 or so, you can buy a toilet auger which should let you retrieve the stuff. Or, pay a plumber to do it for you.
The alternative is to remove the toilet - the clump of paper is probably stuck inside. You can probably push it back out from beneath. If it made it to the pipe, you can probably see it and dig it out. For about $2-3 and a new wax ring to put the toilet back, it might be the cheapest way to go.