From a question i heard on a podcast.

What would I do if I were Prime Minister? 

First of all, let's forget brexit is even happening; I don't want to go down that rabbit hole today.

Police State? 

I would create a single national police force but give regional police commissioners the power to do what they think will work to reduce crime in their district, as long as it doesn't interfear with the national police guidelines. I would legalise weed, and have reviews into the scheduling of other narcotics with the view that regulation is better than criminalization. I would make every officer wear a bodycam to protect themselves and the public. I would also issue out more tazer training and tazers to more officers. I would give police the power to stop and search people that they suspect of committing or about to commit a crime. I would increase CCTV cameras and kit out the national police force with the latest equipment.
The police budget would obviously be increased to cope with all this. Cut the foreign aid budget by 100%. That outta free up aproximately £14billion. But replace it with a new system of aid for commonwealth countries that aren't that well off.

Hopes.

I would try to make our society generally a more safer place to be, a more liberal society where people look let the silly troubles that have them locked in the dark ages; issues such as racism, homophobia, and gender equality.
A culture inspired by science. A society that actually cares about people. Something that people would be proud to be a part of.
If i were Prime Minister I would launch a new emphasis on space exploration and colonization. I don't think enough is being done by our country, let alone the world in this matter.
I would invest a hell of a lot more in social services. A properly funded and staffed NHS is a priority and a neccesity. Decent end of life care for the elders of society or those unfortunate enough to an early departure from our world.
I would fund programs to give people something to do, not just programs for the youth but programs for adults and elders.

Teenagers and what to do with them.

I would give all 16 year olds, once they had finished their general education, the choice between 2 years of either: military service with a focus on education, and no live-combat, or an apprenticeship in any sector you want. Apprenticeships would also actually be worth it. I would pay apprenticeships £1 less than the national mininum wage instead of more than half.
At age 18 after either military service or an apprenticehip is up you would then have to choose between studying a degree at university that takes 3 years, joining the army, doing a higher level apprenticeship for 2 years, or a normal apprenticeship for 2 years. Once you have completed your option, you would then be free to do whatever you want, go on the dole if you become unemployed, go back to university.