Go door to door in your neighborhood with a flyer. "Wanting to start a thrift store. I will be making rounds to pick up items you don’t want on xx date. "

Ask in the flyer for phone calls.

List what you won’t/can’t take.

Rent a truck to pick stuff up. Rent a store front (short term at first with a lease option after 30 days)

Only one way to get started, just get started. Then hire someone and hit the storage auctions.