You don't need to mount CF0: manually, if it's in SYS: Devs/DOSDrivers/ it will be mounted while the OS boots. When CF0: is in SYS: Devs/DOSDrivers/ and CompactFlash.device is in SYS: Devs and Fat95 is in SYS:L/ then CF and SD cards should show up on your desktop as soon as they're inserted. If they don't then it's possible the card is incompatible. If it shows up on the desktop as NDOS then you need to format it by clicking on the icon and selecting Format Disk from the Icon menu. Always Quick Format CF and SD cards!
http://aminet.net/package/disk/misc/cfdhttp://aminet.net/package/disk/misc/fat95It looks like you'll also need these installed, to prevent your Amiga from locking up when the PCMCIA card is inserted:
http://aminet.net/package/util/boot/CardPatchhttp://aminet.net/package/util/boot/CardResetYou should look on those disks for the files I mentioned if you don't have a way to get them from Aminet yet. Remember to select the option "Show -> All Files" from the Window menu so you can see all the files which don't have icons. Drag and drop the three important files from the floppy disk to your hard drive if they haven't already been copied by the installer. Remember, they're: CompactFlash.device, Fat95, and CF0. If all of those files are already in the right places, then it's possible the CF card you're using isn't compatible with the reader. I don't know why they would still be doing it, but a few years ago AmigaKit were selling PCMCIA adapters with incompatible CF cards, so many people had to buy their own CF card to even test if it works. Have you tried another CF card in the adapter?
The only other thing I can think of which might be preventing it from working is the PCMCIA bug, which should be fixed by those two patches. If you try again and your Amiga locks up, simply re-insert the card and see if control is regained. If you can't get a CF card to show up on Workbench still and you need to install those patches you should use a PC-formatted floppy disk. Get a regular disk and cover the extra hole, NOT the copy-protect hole with the sliding tab, with a piece of tape. Cover both sides of the hole. Now insert it in the Amiga and select the PC0 icon that appears on the desktop, then select Format Disk from the Icon menu. If the PC0 icon doesn't appear on Workbench, use the Format program in the System drawer. Once you have formatted the disk as a 720kb DOS disk, you can use it in a PC to copy the files onto, then put them in your Amiga. I just hope you have an old enough PC to be able to read double-density floppy disks.