You can easily calculate this by looking at the current date and subtracting it from May 11. But without knowing the current date, I can't give you an exact number of days.
The number of days until fall varies each year. If it's around the start of September, you might have a few weeks to go. Check a calendar or a seasonal chart to get a more precise count.
Well, that depends on when Comic Con is scheduled. You'll need to look at the specific date and then calculate the days from today. It could be a few weeks or months away.