I live next to a very deprived town, and lived there myself for years.
I'd set up some amazing kids clubs/youth clubs. I'd pay for staff, security, projects, entertainment, support services. Whatever was needed. And then I'd set up pick up and drop off transport for them all.
And I'd do something to support young parents in getting a decent start to family life. Again, whatever I could. Cover childcare costs, provide housing, driving lessons, etc.
I'd try and do something about the drug and alcohol problem. But where to begin?
And I'd make sure our local hospice never again had to crowd fund for stuff like a new boiler 
Same for the pet rescue.
I do have a big family/circle of friends, and I would spend a good 10 million or so sorting them out.
Then I'd set myself up in my dream hobby/job. And have two hourly massages every week 
If we're talking Euromillions amount, I'd be happy to keep 3 million for me. The rest would go on the above and wherever else I could make a difference.