Yes! Apply now! Without paying extra, it takes 4-6 weeks to get your passport!
Yes!
U.S. and Canadian citizen children under the age of 16 (or under 19, if traveling with a school, religious group, or other youth group) need only present a birth certificate or other proof of citizenship. The birth certificate can be original, photocopy, or certified copy. https://www.cbp.gov/travel/us-citizens/western-hemisphere-travel-initiative
Yes, as safe as it is to drive anywhere else!
Yes, Mexican car insurance is recommended. You can apply and get it online. https://www.bajabound.com/
If you have an international plan, yes. If you don't, your phone's map function will continue to track your progress even if you do not have cell service. This is very helpful for getting around!
Santuario Diegueño is about an hour from the Tijuana border entry and maybe 3 minutes from the Tecate border entry.
Typically there's no wait to get into Mexico. When returning to the US, it depends on the time of day. Be sure to check the online border wait times! https://apps.cbp.gov/bwt/mobile.asp?action=n&pn=2505
Definitely not. You can stay in San Diego, e.g., Chula Vista, and make the hour drive in through the Tijuana border to and from the venue.
The border entry 3 minutes from the venue is open from 5AM to 11PM. The border in Tijuana does not close, but it's an hour away.
Parking will be free and easy onsite at the venue.
It will be warm during the day and will cool off in the evening. Bring a swimsuit and a light jacket.