What do I need to make my own CD’s on my iMac 24” running macOS Sonoma?

You need an external CD/DVD writer (aka burner) drive. There are many choices in the market.

I use a Pioneer BDR-XD07s (the current model is BDR-XD08s) and it works great. OWC also has very good CD/DVD writers. But I would not recommend the Apple USB Superdrive. Most drives connect to your iMac with a USB cable (usually included with the drive). It would also be best to get a drive that has its own power supply, not a bus-powered drive.

If you only need to create audio CDs you can use the Music app (formerly iTunes) that comes with all Macs. Import your song tracks into Music, make a playlist and then you can burn the playlist to a CD. Do note that you are generally limited to about 60 min of music on a CD.

You would need an external CD/DVD writer, there are many options available to you at www.macsale.coms. I would recommend calling them and explaining the types of projects you would like to do and they can help you with an appropriate device for your needs. You will also likely need some third party software however what we cannot predict as you only stated "I want to make my own CD's for my old car." which tells us nothing we can use.

If you get an optical drive from OWC, I would suggest getting one of the desktop models with its own power supply. The portable bus-powered drive might need to connect to two of your ports to draw enough power, and while I had a Mac Studio, I still didn't want to deal with that.

I recommend...

https://www.amazon.com/External-Optical-Portable-MacBook-Windows/dp/B0BYHDW4G9/ref=sr_1_16?

& Burn.app, I assume it works on 2024 iMacs, cannot test...

https://burn-osx.sourceforge.io/Pages/English/home.html

I agree with the others regarding a self powered optical drive.

If you want to create music CDs for playing in your car you can use the Music app and create playlists to burn to CDs as music CD.

Also when burning burn at the slowest speed available to get the best burn possible.

Here are instructions on how to do it:

Create CDs and DVDs in Music on Mac - Apple Support

Note that many cars now can actually play CD's full of mp3's, you don't need an actual "red book" CD.