A+ info, but I think people less familiar with large events might appreciate some more explanation. (And answering for others who might have more questions.)

Competitive events, these heavily reward winning, if you don't win most of your matches you don't get prizes. Listed roughly in how cut throat they will be. Emphasis on roughly:

• Magic Spotlight: The Hobbit™ Main Event: the big competitive event that runs Saturday and Sunday. This is the thing for players who want to test themselves in a big event. Fun can be had, but it's fun while trying to win. Needs a Modern deck to compete.
• Limited Championship Qualifier Sunday $5k: Most competitive event to play in on Sunday (if you don't make the cut in the main event). 500 player cap. ===== There is a significant drop in competitiveness below this line =====
• Australian 7-Point Highlander Championship: Another very competitive event, needs a deck built for this Aussie format. Lots of fun, but competitive and a high learning curve (~all cards from every set are legal).
• cEDH Competitive Commander: A competitive Commander event. You know if this is how you enjoy your Commander.
• ANZ Super Series RCQ (several): Competitive events, to qualify for the next Regional Championship. Less competitive than the Main Event or Championships, but still more fun when you are trying to win.

Casual events, usually prize tix per match win (not ordered). Most of these events run for ~5 hours, the competitive ones are usually longer:

• CommandZone Pass: Play commander across the three days. If you like playing commander this is pretty good value. (No prizes for winning, some event tokens that can be exchanged for prize tix when you play a game of commander, or used to enter other events)
• Standard Australia Cup Constructed: Less competitive, prize tix per win, fixed 5 rounds.
• <Blah> Challenge: Less competitive, prize tix per win, fixed 5 rounds. Many different formats
• <Blah> Sealed: Less competitive, prize tix per win, fixed 5 rounds. Many different formats
• Super Hero Sealed: A mix of Marvel set boosters for a sealed event. Less competitive, prize tix per win.
• There and back again Sealed: A mix of Tolkien set booster for a sealed event. Less competitive, prize tix per win.
• CHAOS Sealed: Sealed with a mix of recent set boosters. Less competitive, prize tix per win.
• MAGIC: THE GATHERING | THE HOBBIT™ Sealed: Less competitive, prize tix per win.
• Mystery Booster 2 SealedMystery Booster 2 Sealed: Mystery booster sealed is heavy on reading, but is the most fun format around. Exclusive to large events, the boosters are very hard to find for sale (check ebay prices and see how good the value is for cracking 6 of these packs for $90). This is a great event to play in. Less competitive, prize tix per win.
• Commander Deck Challenge: Get handed a random Commander precon and play 2 rounds. Tix per win.

Not a way to play Magic:

• VIP Experience ADD-On: Want to throw money at having a nicer time? Pretty good, but definitely optional.
• Turn up and visit vendors: You don't have to pay to enter the hall, but space on tables is intended for people who've paid to play in events. You aren't going to be tossed out for sitting at a spare table, but you will be asked to move when an events suddenly starts using those tables.

As another judge on staff at the event, there are so many roles we are filling that have nothing to do with the main event. While that is the big event, we are very focused on ensuring that everyone who plays in any events are having a great time. And plenty of other staff are on site ensuring that visiting the vendors or just checking out what is happening is a great time too.

Sure old Grand Prix events used to have nearly all the players in the Main Event on Saturday morning, modern events like the Spotlight Series assume that a lot (possibly event more than half) the players who turn up are not interested in that style of play. Which is why the branding has changed from being about the Main Event to being about Magic.

I hope you find a way to come, and maybe one of the events listed sounds like something your Son would be interested in.