Thats why its best to get all these things figured out now, eggs a couple days older wont be as bad as putting new fresh eggs in a bator thats not ready for them .
Take a deep breath and enjoy as much as you can this is soooooo cool even if it can be nerver whracking and heartbreaking too.
PS , just in case i miss stuff and you end up putting the eggs in , remmber when you put the eggs in the humidity and temp can change as the eggs become at one with the inside eviroment of the bator , there is no reason to adjust anything unless everything stays diffrent for more then 12 hours . Uless you have a big temp spike that dosnt count , usually what happens to me is my humidity goes up a little and my temp drops into the low 90s as the eggs warm up .