I’m going to ask even though most of you want answer me

As somone who frequently goes on trips i don't have enough cash for, 150 dollars a day minimum. If you stick to tourists areas of any American city you'll need 20 dollars per meal, 15 per drink, 30 per uber/taxi then triple it for the west coast. Since he has his food paid for and assumingly won't be drinking much he could get by on less but 100 euros won't last 6 hours out in Santa Monica or sunset strip.

there are too many variables involved to make any meaningful predictions.

First off.... He might meet a girl.!
Thats double the $$ because you know he is going to meet someone within 2 weeks.

Next off..... What part of L A is he visiting?
He might need bail money for drinking under age.

Then there's traveling expenses..... Bus or taxi if he wants to catch a show somewhere(with a girl).

I'd put it all summed up to $2,000

I’d go with $100 per day. Would rather he have too much money than not enough.

How old is he? A night out in a bar here could cost $100 easily.

I would look at $25/day.

None.

how old is he

$500.00 should cover incidental expenses for a couple weeks.

That depends on how much of a good time you want him to have. Bare minimum would be $20 a day. A hundred a day insures a really good time. Of course your finances play a huge part in this too.

$800 to $1,000

Teenager...$20 per day
Adult...$50-$100 per day