once you've filled out everything you want, you need to set the target IVs. If you're going for a hidden power, and you know the IVs necessary for that, set the IVs, etc. If it's stuff like timid/modest or adamant/ jolly, you can leave attack/SpA blank, respectively--that will increase your options for targets.
After you've done that, click "generate". A list of spreads with numbers that fit your criteria, "A", and "B" should pop up.
"A" means that particular IV is passed to the egg by the first parent you stick in the daycare
"B" is the exact same thing as A, only that it comes from the second parent you stick in the daycare.
Find a few spreads that get the IVs you want, VM me again and we'll continue from there.