To save or load all the slots, you can call the function from the Skill Tree Manager (AC_SkillTreeSystem).
Get Skill Tree Manager -> Call Save/Load/Delete function
Example from the WB_SkillTreeSlot:
Load Skill Tree: Loads all skill tree slots from the saved data.
Save Skill Tree: Saves all skill tree slots and their details to the save game.
Delete Skill Tree Save Data: Deletes all the save data for the skill tree.
If you want to save the skills each time on is acquired, you can open a blueprint, press "Ctrl + Shift + F" to bring up the global search and search for "Saving Todo". This will bring up all the places where you need to connect the saving to.
