Establish the company, secure the lease, registration and bond, and fund the account first; then apply at the consulate and attend the interview. Trading begins after visa issuance and admission. Allow several months and do not broker loads from inside the United States before then.
Set up, apply, then trade: the order is fixed
Hypothetical example: the owner wants to start moving loads for a U.S. shipper next quarter. The realistic path is to form the U.S.
company and obtain its tax registration, sign the lease, complete the federal broker registration and bond, bind insurance, fund the operating account, gather shipper letters and prepare the plan; then file the consular application with the enterprise evidence and wait for an interview date at a U.S. consulate, which varies with demand. After issuance she is admitted at a port of entry and the brokerage begins operating.
Until then she should not arrange or dispatch loads from inside the United States; her Canadian brokerage may continue serving its own customers from Saskatchewan. If the shipper cannot wait, the Canadian brokerage can handle the freight under its existing authority in the interim. Book the family's move and the children's school start after the visa exists, and keep passports valid well beyond the intended period, since visa validity is tied to them.