First and foremost, from the sounds of it, you haven't read the book. You really need to read the second edition print of the book and that will help a LOT! I know that feeling of urgency wanting to start, but it will really help you tremendously to buy the book and read it cover to cover. Next, EXCELLENT on keeping up with your food! That's one of the hardest things is to track the food.

Now, on to your questions.
Ketosis is reached after just a couple of days of very low carbs for most people. By this point, you're probably there! You can buy what they call Ketostix at most pharmacy's and they don't cost much. They'll tell you if you're even in a light state of Ketosis. As far as lean muscle, you won't burn lean muscle unless you are already VERY thin. Your body prefers to get the cals from fat as it is the easiest to break down next to incoming carbs. So, no worries on losing the good muscle! Many, many MANY foods have hidden carbs. The best way to do this diet is to really read labels of any processed foods you use. After a while, it will just become second nature to eat mostly lean fresh meats and whole foods. Why? Well, because there's nothing hidden! Many regular products are bulked with carbs, sweetened with carbs, and preserved with carbs. Even Sugar free items that SEEM like they would be ok, ARE NOT. They've just gotten good at manipulating and hiding them. So, the more natural and whole you can go, the better. The best thing is, after you've done this for a bit, food will take on a whole new level of flavor once your mouth and system aren't being flooded with artificial things.
I know you are in Induction, so my menu may not be of much help to you, but maybe that way you know what will come later. And it also changes depending on my mood. I am in OWL (Ongoing Weight Loss).
Breakfast: 3 eggs with 1/4c monterey jack cheese. 2oz. strawberries and 2oz. blackberries. coffee with 1 Tbsp. heavy cream, 1 Splenda and 1 Sweetleaf
Lunch: 1 1/2c. salad (usually Spinach) with 1 Tbsp. Caesar dressing and 4 to 6oz. chicken breast OR a protein shake (I make my own so I don't have to use artificial anything)
Snack: I either have a snack plate (2oz. cheese, 2oz meat, and olives or pickles) or a yogurt bowl (1/4c. fage, 1oz. pecans, 2oz. strawberries)
Dinner: 6oz. strip steak, 1c. green beans and sometimes a small salad about 3/4c.
Dessert: 1/2c. LC ice cream (I don't eat this very often, but it is a nice change sometimes) OR a cup of decaf coffee/hot tea
And then water. As much water as I can drink being on the go all the time. At least 2L if not more. I hope this has helped some. But getting the book will really help. It can be a boring read, but there are so many tips in there that it will really help. Good luck!