The TurboTax online editions for tax year 2023 are not yet available. They should be available in early December.
Once the 2023 online editions are available you can start with the Free edition. However, the TurboTax Free online edition is for very simple tax returns that do not require any other form or schedule other than the Form 1040. If your tax data requires entry on any other form or schedule then you must upgrade to the Deluxe edition or higher.
The TurboTax desktop CD/Download editions for tax year 2023 are available for purchase here - https://turbotax.intuit.com/personal-taxes/cd-download/
TurboTax Basic is a CD/Download software product that you install on your Windows or Mac computer. There is no TurboTax Online Basic. If you want to use TurboTax Online, the editions that will be available for 2023 tax returns are Free Edition, Deluxe, and Premium. (Premium is a combination of what used to be called Premier and Self-Employed.)
TurboTax Basic CD/Download is available now at the link that DoninGA posted above. TurboTax Online should be available in early December.