From what I know there are no "New Game" options ATM in CK5, you have to own a code like at the end of CK4 to start a game like Fritzerung mentioned 2 posts up.
I'm planning on doing a full run again of the full series, so I'll drop my code at the end of each episode in one neatly done message for anyone who wants to replay any episode on their own. In the near future lol.
In personal opinion, the only problem with this game would be the very lack of story. You have to, I guess, "pound" your way deeper in hell to wake up some senses from the princesses who have gone rogue... And that's all we get lol GET TO IT
But aside from that, this game is sooo great! Art is outstanding and captivating, to say the least. The level-up system feels very fair and the powers that you get from your covenants on your way are all unique and fun to use out and in battle. There's just enough grind that it doesn't get repetitive, plus you usually get awarded different animations from the same enemies multiple times. If anyone is hesitating to try this game, go for it it is ABSOLUTELY worth your time!