assuming BIOS/legacy/CSM mode
DOS/MBR partition 1 -- / -- 25 GiB -- MARK AS BOOTABLE FOR SYSLINUX -- EXT4 partition 2 -- SWAP -- 7 GiB (the rest of the disk e.g. for /data/)
the slackware installer prompts for install settings, here are some answers
if you went for a short hostname then also tune
/etc/hosts so it resolves
see postinstall for a full-blown sysprep
Unless that’s current or you went boostrap, you are outdated already. you need to upgrade your system!
slackpkg update slackpkg upgrade-all
is your console a shitty one?
then you need to enable SSH password auth temporarily, just to push your public keys over there.
or you got a true console with the advantage of being copy/paste capable?
then just edit authorized keys and switch to SSH already.