Whether you used pcgen.bat or pcgen.jar to start up PCGen, the first thing you will see is the splash screen with the man/machine DaVinci logo and the words PCGen written across it.
From there, PCGen will load and take you to the Source Material Screen where you can get started making your characters!
It is recommended that before you start, you go into the Settings Menu and configure how you want everything to look, from the actual PCGen look and Feel (using skins), to the manner that the character name is to be shown on the character tabs, to your browser location! Setting all these configurations before you start making your character is highly recommended, as some setting will impact how your character is made, such as hit point rolling methods, starting gold and many other options!