United play the Los Angeles Galaxy on Wednesday before heading to Denver, Washington DC and Ann Arbor.
After arriving at Los Angeles International on Friday night, Van Gaal and his players headed straight for the beach and then, after a brief stroll, to the Beverly Hills Hotel where they will spend the next six nights.
Ryan Giggs, Darren Fletcher and Juan Mata all signed autographs for some of the 100-plus fans who had gathered to greet them.
Van Gaal and his squad will train at the Stubhub Center, home of the Galaxy, on Saturday.
Youth-team products Sam Johnstone, Tyler Blackett, Michael Keane, Reece James, Jesse Lingard and Will Keane are part of the touring party, but there was no room for James Wilson and Tom Lawrence, who made their first-term debuts at the end of last season.
United had announced earlier this month that stars like Wayne Rooney, David De Gea and Mata would travel to the US along with new signings Luke Shaw and Ander Herrera.
Robin van Persie, Javier Hernandez, Marouane Fellaini and Adnan Januzaj are still on holiday after the World Cup.
Michael Carrick is a notable absentee after undergoing ankle surgery on Thursday morning that could rule him out for the first two months of the season.
In his first press conference on Thursday, Van Gaal said he would spend the next three or four weeks assessing the players he has at his disposal before deciding on potential new signings and departures.