I am unable to enter my self employment income for 2024. There is already an amount entered which I did not enter and it doesn't look like I can edit the amount.

Did you enter a 1099-NEC? If so, this would go to your Schedule C.   If you did, this is where the number came from.  If you are in forms mode, you can only change numbers that are in blue.  If they are in black they are coming from a worksheet.  Click on the number in black and then click the magnifying glass to go to the worksheet.  

Please note, that entering the numbers directly on the forms will void the TurboTax accuracy guarantee. 

To enter your self-employment income select the following:

1. Federal
2. Income and Expenses
3. Show More next to Self-Employment
4. Start next to Self-Employment
5. Yes, to you have any self-employment income or expenses
6. Enter the type of self-employment work you do and you can select that you use your name for your business
7. Click through a few more screens and you will get to a screen that says "Your XX info"
8. Click Looks good
9. Then you will come to a screen that says Let's enter the income for your business.  It will give you the option of 1099-NEC or Other self-employed income including the 1099K , cash and checks.  Here is where you will enter the money you receive.
10. If you do not select one, it will not let you enter your income
11. Enter your self-employment income on the next screen
12. Continue and on the next screen click add expenses

* navigation may differ slightly depending on which version of TurboTax you are using*