The IRS doesn't require the individual income tax returns for 2023 to be filed until (at the earliest) April 15th, 2024...several weeks after your N-400 appointment. Feel free to bring anything you want to provide for the 2023 tax year. If you have already done your taxes, bring copies of your return and supporting documents (W-2, 1099, etc.). If they ask about your 2023 return and you haven't done it yet, you can assure them that you plan to file on schedule. You can certainly look and see if the 2023 transcript is available, but do not count on it. (No one knows the IRS' schedule for such things.)
You don't "order" a tax transcript. Once you've logged into the IRS web site, if a given year's transcript is available, you can click on it and download it immediately.
For a data point, I filed our federal return earlier this week. The only 2023 transcript currently available to me on the IRS website is the Wage & Income Transcript. If I create it, it says "No return of record filed." It's too soon.
Take 2018-2022 with you. You got this.
Regards,
Vicky's Mom