I earned $300 from craigslist gigs how do I add this to my income for the year when filing taxes

Since you are using LIVE, ask your expert.

https://ttlc.intuit.com/turbotax-support/en-us/help-article/product-setup/connect-tax-expert-turbotax-live/L73wOZD5D_US_en_US?uid=lfiz6cgp

Casual sale of personal items may be reported on Schedule D IRS form 1040 and Schedule 8949.

Personal items sold for less than their basis (most likely, the original purchase price) report $0 capital gain on line 7 of the Federal 1040 tax return.

Personal items sold for more than their basis report the gain on line 7 of the Federal 1040 tax return.  See this example.

                                              Selling                   Cost

                                              Price                      Basis

Item 1                                   $500                       $2,000                 Capital loss on personal item = $0 loss

Item 2                                   $400                       $300                    Capital gain on personal item = $100 gain

Item 3                                   $100                       $100                    No capital gain or loss

                                              $1,000                   $2,400

To report such a casual sale of personal items, follow these directions.

• Down the left side of the screen, click Federal.
• Down the left side of the screen, click Wages & Income.
• You may need to click Add more income.
• Scroll down to Investments and Savings and click on the dropdown menu.
• Click Start to the right of Stocks, Cryptocurrency, Mutual Funds, Bonds, Other.
• At the screen OK, let's start with one investment type, select Other, Land, Second homes, Personal items.

See also this TurboTax Help.

@henrybrownjr89-g