Hello, and welcome to the game.
Particracy is no longer opening up new nations, as coding of the game has stopped. However, in culturally open countries, you are allowed to role play however you want (within the other game rules) and over time it's possible to give the nation a completely new identity. This is the closest thing you'll get to a fresh start. Countries are listed by cultural status here:
viewtopic.php?f=5&t=6365