You may need to install a driver for the nvidia. See the Slackware forum here at LQ for the best advice.
If HWSETUP finished successfully, your fstab should be setup with an entry for your cdrom. Check like this:
ls /mnt
If it shows cdrom, or cdrw0 then do:
mount /mnt/cdrom0 (cdrw0)
then:
cd /mnt/cdrom
ls
Sorry there are no pretty CLI text editors, just vi!
Safest way to edit a file is to open it with 'less' then edit it:
less /etc/X11/Xf86Config
Then, using arrow keys, scroll to the relevant spot. type:
vi then hit ENTER, less enters into 'vi' mode. edit, then exit vi normally. That drpoy you back to 'less', press 'q' to quit less.
You don't need to know too much to use vi. When it opens, it is insert 'mode'. push <ESC> to quit insert mode, or any mode. Use cursor keys to navigate.
To delete characters push 'x' (deletes under and to the right). When finished deleting push <ESC>. Push 'i' to put in 'insert' mode. after adding characters, push <ESC> to stop inserting. To save the file do:
:
wq
WHen you push the colon (

. the cursor goes to the bootom of the screen. Then push wq (write-quit) to save.
Or 'q!' to quit without saving.
The package manager is pkgtool.
I suspect you did the EASY method setup. You can run the whole HWSETUP routine again and try a different method if you like. Probably Xconfigurator would be bets. To run HWSETUP do this:
from CLI run '/usr/lib/amigosetup/pristine'
then:
/usr/lib/amigosetup/firstrun (or reboot)