can I connect a external dvd player to the iMac 24 with 2 usb slots

Remember that the Apple DVD drive, the USB SuperDrive, will not work though a hub and needs to be connected directly to the computer, and may require an Apple-branded adapter. If you do not have an available port on that iMac, your need to consider a different DVD drive tath works with a hub. I am considering this one for my iMac:

https://eshop.macsales.com/item/OWC/MR3USD24/

It is self-powered (has its own independent power supply) so can work with a hub, is a much newer and faster design (the Apple drive has not been updated since 2012), and uses the more reliable tray-load design. Another advantage is that, if your new puppy or kitty chews through the data cable, you simply get another $7 cable. If the pets get to the Apple SuperDrive's integral cable, that's a new drive for 10X the cost of a cable.

👉🏻 I have no relation with the company I mention other than as a customer. I get nothing for mentioning them.

Yes, as long as the CD/DVD player has a USB-C connector or you have a USB to USB-C adapter.

my external asus blueray/dvd/cd burner comes with an usb cable that splits up into 2 usb-a ports

because it requires more power than a single usb-a port can provide, but ofcause I only connect the data usb port to my computer the other connector goes into an ac charger with an usb-a port it in

Interesting. An Apple SuperDrive works fine in an M1 MacBook Air plugged into just one port.

well maybe the asus drive requires more power, it requires 2 usb ports on all computers

So it seems.