I’m getting life insurance and for the time being I want it to go to my two nephews.

They are very young. Do I just put their names as the payees? Or should I make a trust for them and have my brother be the trustee and invest and distribute the money to them when they turn 18?

Any advice is appreciated.

#1 Trust, for sure. It allows you to exercise some wise, educated control over the money.

#2 think back to when you and your brother were 18. Would you have handled a large chunk of money wisely? Some people would have, but most wouldn't. Even if they are good kids, a large chunk of money that early in life can have big psychological effects and can ruin them similar to how the lottery ruins people. That is most likely an amount of money a few orders of magnitude larger than they've ever seen before. Payout at 18 isn't advisable IMHO. I would have it pay a very small percentage annually with payouts getting significantly larger after age 25.

Of course you can always write exceptions into the trust. They can get larger payouts for qualified education expenses, purchase of a home, business etc...

This kind of protection is provided with a Spendthrift Trust.

In many states, if you leave it just to them, and they are minors when they receive it, then a parent or guardian has to set up some kind of court-ordered vehicle to receive it and hold it until they are adults, I don't remember the name.  It's a PITA to do, and it kinda screws the kids' parents (and the kids if the parents never do it).

However, making a trust is much, much easier, and the distribution is on YOUR terms, not the Court's.

18, 21, or make one of their parents put the family trust with restrictions.

Beneficiaries had to be 30 to get direct control of their portions.

Trust run by their parents till whatever age you think they will be responsible at.
At least mid 20s usually.