where do i put self-employed expenses

Your business expenses must go on a Schedule C.   If you are using online TurboTax you need to use Premium.

If you have self-employment income for which you will pay self-employment tax for Social Security and Medicare,  you will need to use online Premium software or any version of the desktop software download so that you can prepare a Schedule C for your business expenses.

https://ttlc.intuit.com/community/self-employed/help/how-do-i-report-income-from-self-employment/00/26653

https://ttlc.intuit.com/community/self-employed/help/what-is-the-self-employment-tax/00/25922

If you live in a state with a state income tax, you might need to make estimated payments to your state.

https://turbotax.intuit.com/tax-tips/small-business-taxes/the-home-office-deduction/L1RZyYxzv

https://turbotax.intuit.com/tax-tools/calculators/self-employed/

https://ttlc.intuit.com/community/business-taxes/discussion/self-employed-don-t-miss-these-tax-moves/00/3400413

https://ttlc.intuit.com/turbotax-support/en-us/help-article/import-export-data-files/enter-schedule-c/L5Fz3j5us_US_en_US?uid=m6a6gknk

https://ttlc.intuit.com/turbotax-support/en-us/help-article/payroll-additions-deductions/qualify-qualified-business-income-deduction/L0rM2cIIQ_US_en_US?uid=m5zpoxad

https://ttlc.intuit.com/turbotax-support/en-us/help-article/self-employment-taxes/self-employed-expenses-deduct/L37ZS1B8T_US_en_US?uid=m6fntpg7

What version are you in?   You can enter Self Employment Income into Online Deluxe but if you have any expenses you will have to upgrade to Premium version. Or use any of the Desktop CD/Download programs.

Where to enter business expenses
https://ttlc.intuit.com/community/entering-importing/help/where-do-i-enter-my-self-employment-business-expenses-like-home-office-vehicle-mileage-and-supplies/01/27109