Best check the specs for the particular infotainment system.
Also check that the car manufacturer’s firmware for the infotainment system is the most current.
Usual preferred connection now would be Bluetooth, or less commonly USB wired.
Bluetooth audio is probably the most common choice, and an increasing number of Infotainment systems offer Apple CarPlay.
Most infotainment systems will play from iPhone via Bluetooth or CarPlay, and many from iPod touch or iPad via Bluetooth.
Various infotainment systems will play directly from USB flash drives, though the format of the files and directories stored there needs ro be set up as expected for the infotainment system.
Other systems will have an analog audio input (3.5mm stereo jack) and can accept audio input from that connection, and an iPod nano does have an audio output jack.
If you want more suggestions here or advice tailored to your infotainment system, you’ll need to identify exactly which model of infotainment system is installed here.