Yes, I agree with Teddy, in the first stage, it is best to start drawing in the paper. This will help you clearly understand the structure of the device (MOS, Bipolar, BiCMOS). Then you can just use some simple tools that will help you automatically convert your schematic design to physical layout. Of course, this type of software is not serious for the layout design, but could helps you to understand where and how many contacts you need to put, or solve delays issuers in metal bus if you working with RF design and so on.