Actually The threshold for filing your taxes for self-employment income is only $400 not 600. The 600 is the amount someone has to issue you a 1099NEC. And you have to report all your income whether or not you get the 1099.
You don't file to get a sole proprietor unless you want to be a LLC. You just file your self employment income on schedule C in your personal tax return. Sole Proprietor/Freelance/Independent Contractor are all the same thing.
Sales tax is a separate thing you file with your state or county. Turbo Tax does not do Sales Tax returns.
Some general info on self employment on Schedule C.......
You will need to keep good records. You may get a 1099NEC or 1099K at the end of the year if someone pays you more than $600 but you need to report all your income no matter how small. You might want to use Quicken or QuickBooks to keep track of your income and expenses.
There is also QuickBooks Self Employment bundle you can check out which includes one Turbo Tax Online Self Employed return....
https://quickbooks.intuit.com/self-employed
When you are self employed you are in business for yourself and the person or company that pays you is your customer or client.
To report your self employment income you will fill out schedule C in your personal 1040 tax return and pay SE self employment Tax. You will need to use the Online Self Employed version or any Desktop program but the Desktop Home & Business version will have the most help.
Turbo Tax Beginners Tax Guide for the Self Employed
https://turbotax.intuit.com/tax-tips/self-employment-taxes/beginners-tax-guide-for-the-self-employed...
What is form 1099NEC?
https://turbotax.intuit.com/tax-tips/irs-tax-forms/what-is-form-1099-nec/L5fbwIFSn
Here is some IRS reading material……
IRS information on Self Employment
https://www.irs.gov/businesses/small-businesses-self-employed/self-employed-individuals-tax-center
Publication 334, Tax Guide for Small Business
https://www.irs.gov/pub/irs-pdf/p334.pdf
Publication 535 Business Expenses
https://www.irs.gov/pub/irs-pdf/p535.pdf
You pay Self Employment tax on $400 or more of net profit from self-employment in addition to any regular income tax. You pay 15.3% SE tax on 92.35% of your Net Profit greater than $400. The 15.3% self employed SE Tax is to pay both the employer part and employee part of Social Security and Medicare. So you get social security credit for it when you retire.
