Others have answered your EE questions. But didn't see anything about the CA entrance. If you go through the GC lobby, past the pool, there's a walkway out to the park that let's you in near Grizzly River Rapids. You will have to show proof of staying at a Disney hotel, but doesn't have to be the GC.
Others were talking about breakfast, please don't waste your precious early entry hours looking for food. Grab something before you enter so you can take full advantage of your early time on the rides. Even after the park opens, you're still going to get great ride time for about 1 1/2 more hours. Then take a break just as the rest of the crowd starts waking up.
But if you're going to CA, through the GC entrance, stop by White Water Snacks to the right of the CA entrance hall. They have quick cold breakfast items, plus hot food. Big portions at a decent price. A great option for lunch too.