By law you can't remain anonymous. You have to claim it publicly.
First thing I do? Pay off my debts. Then I'd give my mom a shit ton of money so her and my dad can retire very comfortably. They've given me more than I could ever ask for, I want to pay it forward. Next, I'd help out my friends in any way that I can with any issues they have. I wouldn't set them up for life, but any debts they have, I'd like to clear those for them. Then, I'd buy a decent sized house, maybe 2,500 SQFT, have an outdoor shed that's a dedicated game room where friends can hang, stay the night if they wish, and I'd put the rest of the money into investments/savings.