Trying to Pay Estimated Taxes for 2024

In 2023 I was employed as a FTE (on a W2) and had taxes withheld normally.

In 2024, I am employed as a FTE (W2) **and** I am self-employed on a 1099 for 6 months of the year (starting June). 

I know I will need to pay self-employment taxes in 2024 and I'm having challenges estimating them. Here's are the questions I'm hoping for answers to:

• Can I use TurboTax 2023 to estimate my 2024 self-employment taxes? (Keep in mind I didn't have self-employment income in 2023.) If so, how?
  • I did locate this article but the instructions fall flat on #1. (Search takes me to the TurboTax Assistant (AI); it does not retrieve the form or offer a "jump to" option.) Can TurboTax calculate next year's federal estimated taxes? (intuit.com)
• Can anyone direct me to help in completing 1040-ES? I downloaded the full packet but on p. 8, 2024 Estimated Tax Worksheet, it asks for AGI expected in 2024 (see instructions) and but it doesn't say which instructions and how to estimate AGI. 

Appreciate any help from the community. Thank you.