Best Missed Expense

We have no information from you as to what kind of business you have.

https://ttlc.intuit.com/questions/3398950-what-self-employed-expenses-can-i-deduct

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 CD/download so that you can prepare a Schedule C for your business expenses.

https://ttlc.intuit.com/questions/2926899-how-does-my-side-job-affect-my-taxes

https://ttlc.intuit.com/turbotax-support/en-us/help-article/form-1099-nec/1099-nec/L5qTsBiSe_US_en_US

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

https://ttlc.intuit.com/questions/2902389-why-am-i-paying-self-employment-tax

https://ttlc.intuit.com/questions/1901340-where-do-i-enter-schedule-c

https://blog.turbotax.intuit.com/self-employed/self-employed-tax-deductions-

calculator-2021-2022-50907/

https://ttlc.intuit.com/questions/1901110-do-i-need-to-make-estimated-tax-payments-to-the-irs

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-tools/calculators/self-employed/

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

Hello @MtnMatt congratulations on your self-employment!  

Depreciation is one deduction that frequently gets overlooked.  Large expenses for equipment, property, etc. need to be depreciated over the useful life of the item.

Start up costs need to be amortized but up to $5,000 can be expensed in the first year if they qualify.

Helpful Links:

What self-employed expenses can I deduct? 

Taking Business Tax Deductions 

20 Tax Deductions for Self-Employed People