Thanks to turbotax, I received the second stimulus payments, but I missed the first. Am I able to receive them again, or I will never have the first stimulus.

If you do not receive any other stimulus payments by January 15, 2021, then the stimulus payment for which you are eligible to receive will be entered on your 2020 federal tax return as a tax credit on Form 1040 Line 30.

The TurboTax program will ask about stimulus payments in the Federal Review section of the program.

you'll get it but just in another way

enter the payments you did receive in the Federal Review Section in Turbo Tax and then look on Line 30 of Form 1040 where the missing money should be displayed - it will have the effect of increasing your refund (or decreasing what you owe)