If the business was in operation in 2019, you should report it on your 2019 return as self employment.
If the business was not in operation in 2019 you can claim the expenses in 2020 as start up expenses.
Per IRS Pub 535 Business Start-Up and Organizational Costs: "Business start-up and organizational costs are generally capital expenditures. However, you can elect to deduct up to $5,000 of business start-up and $5,000 of organizational costs paid or incurred after October 22, 2004. The $5,000 deduction is reduced by the amount your total start-up or organizational costs exceed $50,000. Any remaining costs must be amortized."
As long as your start-up expenses are less than $5000, you can add them as Business Expenses.