I’ve read the famous lottery post enough times to know the major bullet points to follow after winning (not that I’ll ever win, because I don’t play the lottery):
Don’t tell anyone.
Go to your nearest big city and hire a partnered lawyer in trust & estates from one of the big national law firms. Look them up on martindale.com, apparently.
Decide how you want to split your winnings and have your new lawyer handle the distribution.
Yada yada, typical personal finance investing advice (good to follow even without a lottery).