Thousands of hot meals will be served up and Easter baskets will be given out to children.
Elected officials and celebrities, including Zoe Saldana and Hilary Duff, are expected to take part in the events at the mission, which also is celebrating its 75th anniversary.
Volunteers arrived early to help set up and hand out ham and egg breakfast sandwiches.
"We want to give them a nice, warm meal to start off," said head chef Dave Thomas.
Thomas said the cooks were preparing a ton and a half of ham, 90 gallons of glaze for macaroni and cheese and lots of vegetables.
Etnies will be giving out 2,000 brand new pairs of shoes to the homeless people on Skid Row.
"They spend all their day on their feet, so it's really important that they have durable, comfortable shoes," said Ashton Maxfield of Etnies.