How do you celebrate after getting a $170 MILLION contract offer?
If you're Ben Simmons, you hit the Hollywood nightclubs with a massive entourage!!
That's what the 22-year-old did last night ... rolling into Bootsy Bellows in West Hollywood like the ultimate VIP and TMZ Sports has the video.
Simmons -- looking super casual in a hoodie and a baseball cap -- strolled right past the normies and walked right into the club with a bunch of dudes and ladies surrounding him.
It was a pretty pimp moment from one of the biggest young stars in the NBA.