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

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

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.

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.