Ok...first of all, calm down! You can do this! LOL!!
The way leopard geckos are designed, they only produce 2 eggs at a time. If she's that big, it means she has good weight...which is wonderful because she'll stay plump while producing eggs. It takes a lot out of the girls to produce eggs. (By the way, don't forget to keep ample calcium in with her at all times. She needs a lot right now.)
The reason the information seems vague is because it's a very easy thing to do and there are a few ways to do it.
Hopefully, I can help.
You're on the right track with the incubator and vermiculite. I keep the lid on my plastic container to try to keep the moisture better contained. You can try it either way. If the eggs start to dry out, put the lid on. Don't worry about adding holes to the deli-cup. Just leave it as is. There's enough air inside for the eggs and the incubator is a closed box anyway. There's really no point to adding holes. If you keep water in the incubator and keep the box with the eggs closed, you wont have to add any more water to the vermiculite during incubation.
Bird eggs need to be rotated and reptile eggs are to remain in the position they were laid. Mark the egg with a sharpee to make sure you don't put them back in the wrong position if you must move them. You also may want to number the eggs instead of merely marking the top. This way, if you add eggs as they are laid, you can keep track of the date to know when they should hatch.
Now...on to temperature.
Incubation temperature is important, as it determines sex (as well as plays a roll in coloring). Sex is determined within the first 2-3 weeks of incubation. If you want females, incubate the eggs on low; 79-82 degrees. If you want males, incubater them on high; 87-90. If you want mixed sexes, incubate in the middle range.
I recommend incubating for females because then, if the temperature rises a bit for any reason, your eggs wont be killed. If you incubate at 90 and the temperature spikes up, it may be fatal. I say this because I just noticed that my incubator temperature was 84-85 degrees and I had set at 80! It stayed at 80 for a little while, I have no clue how it went up a few degrees...my kids must have touched something! LOL! I'm just glad I make a habit of checking the temperature once a day. 
Good luck!