trying to make a scoreboard where when i add to it all values go up by 1

when a player gets a skill i can run commands and when i do that im trying to add them to a scoreboard so i can keep track of what order they were bought in so that when the player dies they lose the most recent skill. having trouble figuring out how to properly set this up though. i dont really have anything concrete other than a scoreboard with 2 fake players. one is to keep track of the total, and the other is the first skill im trying to get this working with so that i have an idea of how its supposed to be set up for the rest of the skills. this is all in functions so no need to know anything about the mod im using (its origins and pufferfish skill in case youre wondering) so this is all do able in vanilla with commands and could be used for other things that arent this.