Janet,
By "cups" I mean fruit fly cultures. You buy a cup of hydei fruit flies and separate them into four other cups with fruit fly media in them and then let them sit until they explode with the next generation. By doing this once a week you will end up with more fruit flies than a clutch or two could ever eat! It takes a number of weeks for the fruit flies to mate, lay eggs, and hatch out so you have to do this ahead of time. The length of time depends on the temperature. The high 70s will give you fruit flies in three to four weeks.
The real reason to start more than four weeks before you need them is to practice and get it down. The actual recipe and steps are the easy part and it is pretty hard to mess up, but the discipline takes practice for some people. And I remember finding the most ridiculous ways to screw up the recipe. I needed the practice!
It is frustrating having fly cultures explode and die out before the eggs hatch, but there is no way around this because you don't know when the eggs will actually hatch. And once they hatch you don't have time to start cultures and wait until they produce.
Order crickets only after the babies hatch. Crickets get shipped pretty quickly so you should be fine. But it gets expensive buying and shipping crickets. An active fruit fly culturing will produce much more food cheaper and more reliably.
Bill