If your toilet clogs...
Please attempt to resolve the toilet clog using a plunger. These are available from most hardware and big box stores.
For shower and sink clogs, you may be able to dislodge debris from the pipes using a cleaning tool. Many stores sell plastic cleaners you can thread down the pipe to snag anything stuck in the system.
You can also try chemical cleaners, but only use those that have been approved for plumbing use, as some corrosive products could damage the pipes.