If I installed suse with only a / mount point, can I later format another partition and give it a /home mount point or will it mess anything up? Like will it delete anything that’s in the current home folder?
It should not delete anything but IMO the best way to do it is to make the partition mark it to mount as /home (in Yast-partitioner) rename home (must be root) reboot immediately (this is best done from a terminal ie ctrl-alt-F1, log as root, init 3 [take down GUI], rename , make sure all is well reboot. This should then make a new /home on the new partition… Then copy the files to the new /home from the old. Once done you can remove the old.