Going off the idea that what politicians did/thought as teenagers should be their forever policies, what do you think your teenager(s) would do if they were in charge of the country right now?
To start, mine would ban GCSEs. School would be "less often" and if you weren't enjoying a subject, you could give it up and start something else.
He would overhaul schools generally so they were more fun and nicer places to spend time.
More protein in food. A possible ban on food not containing protein.
Less/no cars, more ebikes.
He would also ban vapes, cigarettes and any street drug that could be laced with something else.