Start going around to banks and pay off mortgages - but only for people with like less than $1000 to $2000 in the bank. that would change lots of lives, quick.

Send everyone 12 dollars.

Build a fusion power plant and put money into fuel production for it.

Buy as much land a possible and build houses for homeless people to rent at an extremely low cost. They would need to either have a job or be actively looking for one (with proof since trying to get one shows they might actually be trying to better their life, in my eyes at least), pay for their own food, and maybe a $10 monthly rent.

The lease would be on a yearly basis and if they find a better place they can afford before the lease is up, they would be allowed to leave without any sort of early lease termination fees. There would probably be a month long period where the person(s) could move back in just in case the new place doesn't work out and they have to move out. During the grace period, nobody can move in.

I would, with the hypothetical money, pay for their utility bills and try to keep up on repairs/maintenance so long as they don't abuse it by doing something like constantly keeping the water on 24/7, using as much electricity as they can physically can, or purposefully breaking and wrecking the place.

Also, I would let them know that they would be responsible if they get their internet access cut off because they were too busy pirating. Even though I personally support piracy, I wouldn't want to be in trouble for piracy that I wasn't directly involved in.