If you're staying on site at WDW, you can select ILL at 7AM. Otherwise, you can't select an ILL until park opening. With ILLs, you select an available time window. You can book 2 ILLs at any point throughout the day, including both at 7AM.
You can purchase G+ anytime after midnight. You can book your first LL at 7AM (whether staying onsite or not), but it's 'next available' time. You cannot choose a specific time. You then can book your next LL 2 hours after your first park opens (often 10:30 or 11AM). Then you can book another 2 hours after that - if you look at your
MDE app, the time will be shown when you're eligible to book another. If you wish to book LLs for later in the day, you should book the attraction ASAP, then check on the app and use MODIFY to push the time later. If you use modify, you won't lose your '2-hr' window for booking your next LL. If you cancel and rebook, the 2-hr window starts over. Hope that answers your questions - there is a ton more detail and info out there on this post - check the first couple pages.....