Guide on character generation:
1. Generate a map (optional)
2. Choose an origin.
3. Choose a belief.
4. Choose a class.
5. Choose a skill.
6. Choose equipment.
7. Choose an artifact.
8. Spend experience points (you start with 1500).
I don't think I forgot anything...
If you choose the "isekai" option (Miss Cosmos becoming a celestial being), the princess will summon you according to the plot. In this case, the game will start for the character at the moment when he wakes up in a new world.