Kay. So I was being pretty negative before. But I had a think about it and actually had an idea that might help you.
This is specifically aimed at targeting minors (hello, FBI).
One of the biggest barriers for entry in to tournament 40k for young people (aside from, you know, the actual cost of the army) is usually just straight up nerves. No one wants to roll up to an event, get their face pounded in, then go home. And let's face it (stereotyping inbound), the kids that love 40k aren't the kids that spend a lot of their time playing sports and learning to win and lose with grace. Especially if you come from a smaller community like a club into a larger one like the state tournament scene, as club players can be very forgiving and don't tend to stress things like redundancy in lists and the game rarely has any stakes behind it.
So going from friendly games with whatever you like to take against people you know to tournament games against complete strangers wielding ridiculous lists can be incredibly intimidating, especially if you're young and they're an adult. It's compounded by the idea that if you've never been to a tournament and played through that sort of structure before, it is all new and also intimidating. Social outcasts, rocking up to huge halls full of people, often by themselves, even though those people speak the same language, is scary.
So, ages ago when I still cared about the kids at our club going to outside 40k events, I started training them with a tournament structure I ended up calling Rapid Fire. The tournaments themselves had the lowest barrier to entry I could think of. Free. They were only open to players under the age of 18 to keep the kids playing at a roughly equivalent skill level and mindset but the tournament structure itself mimicked PAGS' larger events, which were designed as hardcore tournament events. So the idea was to get the kids used to going through the motions of planning their army list, testing it, painting it, arriving on the day and playing through the games, participating in the scoring and going through the results to get to the podium finish, just with kids close to their own age and with nothing really to lose by attending (and the possibility of a shiny trophy at the end). The benefits included it being easy enough to attend and participate in (the games were only 500 points and entry was free) and because it was a single day event, it meant the kids only had to plan to attend one day, rather than play through a league or campaign.
As a short post mortem, Rapid Fire only ever ran two or three events before PAGS stopped running 40k tournos, Had our playerbase stuck with the system, I'd still be running them. But if I was going to change anything, it would be the location. I suggest centralising it somewhere near the CBD and public transport. Mandurah was just too far for kids without accomodating parents to travel and the attendance at the events usually comprised of our guys plus Armadale's younger crew (for the record, pretty sure Owen won the last one right before he turned 18). I still like the idea and if we get another system coming along where the playerbase is at the same point it was with 40k, I'll probably pick it up again under a different name.