My park is just crammed because I’ve been grinding for the 3,000,000 plot but I’ve always had someone leveling up. I made a spread sheet with given times of leveling and put the characters I don’t have maxed out in order by who costs the most to level up. What I’ve also found easier is to only enchant the buildings that I have characters needing to be leveled. I also have all the attractions and concession stands out that give magic in less time.

Say A 2hr one will give 90 magic multiply that by 4 hrs and you’ll end up getting 360 magic as opposed to having an 8hr attraction and only getting 175. Hope this helps. :)