Very new to this. I had an old laptop laying around and wiped out windows and installed Raspberry Pi Desktop. My Cd/dvd works. Usb ports work. But ethernet and wifi are both down.
Does anyone know how I can fix this?
It is difficult to help because it is not a Raspberry Pi you installed the operating system. It is an intel/amd architecture, not an ARM one. I have not used the Raspberry Pi Desktop but I think it is a default Debian installation just with the RasPi Desktop on top of it. So you should look for troubleshooting on debian installations.
I guess the ethernet and wifi devices on your laptop are not supported by drivers out of the box. Look for the error messages in
journalctl -b, examine what chips are used for ethernet and wifi, usually with
lspci. Maybe you need to load firmware to the chips, journalctl will show you this. Various firmware packages you will find with
apt list firmware-*. If unsure what to use look at the details with apt show. For example
apt show firmware-iwlwifi will give you a list what intel wifi adapter are supported by this package.