Hi Andrea and welcome
1. Numbers are given out at an unspecified time, though usually 6ish, and in the order in which folks are in line. You must be present and in line to get a number.
2. You aren't setting up camp in line. Most people use a chair to hold their spot when they use the restroom etc. They may also have a sleeping bag or some other means of staying warm at night. Some of the first people will be sitting in line day and night, that may seem to look like they are camping.
3. You won't be in line until 7:45, so you will be pretty far back, but I would think as long as you aren't trying for the front section, you'll be fine.
Someone else may have better info on what to expect at that time.
Less than 5 weeks to go, woot wooot!!