By new version I assume you mean Conquest, which is basically an entirely new game though they share some similarities. I haven't played it yet, but from what I've heard on the Discord it's starting to become rich in features but poor for intuitive gameplay. It'll probably get smoothed out as Mav progresses the core gameplay further. The first game still has its fair share of non-intuitive mechanics.
Speaking of which, the player character is a bit weird in many ways. The max stats are set by player rather than by race, they can't work any jobs, and the game tries to act as though they don't have traits, though traits are mostly irrelevant to the player character. For instance, the player can still quietly learn sexual traits during sex, but they have no effect. I recommend checking the wiki for traits as Dominant and Submissive are not sexual traits nor would they have any effect on gameplay for the player character. The Role Preference stat indicates whether a person is dominant(higher values) or submissive during sex, but the stat has fairly low impact on the game and is only changed by giving or taking punishing sexual actions.
The core stats (Strength, Agility, Magic Affinity, Endurance) are increased by clicking the "+" icon next to the max stat and uses their free attribute points.
The basic mental stats(Courage, Confidence, Wit, Charm) are increased using the "Learn. Points" menu in the slave tab. Learning points are primarily acquired using the Teach action during the Meet interaction, but also by assigning them to the library.