I think this is the ultimate problem. A year isn't long enough and some of the things that are required won't be popular enough to get you re elected.
I'd reinstate Sure Start, build new social housing. I'd build a healthcare system that deals with causes not symptoms. But that costs and someone's going to have to pay more tax.
I'd take a lot of the current measures that are supposed to help away. Universal free school meals, child benefit for families earning £100k, funded nursery hours. Too many benefits for those who should be able to support themselves.
Mostly I think a huge public education campaign on taking responsibility for your own health, living, children is required. Create an environment where people want to take care of themselves and their families, because the alternative is not socially acceptable. I absolutely don't mean remove the rug from under them, but gradual nudging, and education, to change attitudes.
That's not to bash people who currently have poor health or rely on benefits, but to help them create a better life for themselves because, whilst the state can make things slightly more bearable, they're not going to have "good" lives until they make changes themselves, and that's going to need a complete change of attitude and lots of support. That will cost too.