This could be a couple of things. Are you looking at the right
numbers? Next to the spell level subheader, there is a number for the
total spell slots at that level. This shouldn't be zero for level 1
spells for either a Paladin or a Warlock, and there's something going
wrong with Charactermancer if this is the case. There's a label above
the 1st level spells which says SPELL SLOTS TOTAL for this column, and
the Attribute is @{lvlX_slots_total}, where X is the spell slot level.
You can manually change these in the Attributes & Ablities tab. To
the right of this number is the column labelled SPELL SLOTS REMAINING
above the 1st level section. For some insane reason, the Attribute is
actually called @{lvlX_slots_expended}, the exact opposite of what it
should be. The "Spell Slots Remaining" don't get bumped up to your total
spell slots, probably because way back when this part of the
Charactermancer was coded, they were "spell slots expended" (which is
still the Attribute name), so they will remain at zero. These can be
manually adjusted straight on the spells tab. Making a blank Warlock, with no spells selected (skipping everything possible, like background) gives me the correct result: 1 slot total. It should also increase slots remaining to max (at least at first level) but it doesn't. Out of interest, is this purely SRD? I've got PHB and XGtE, so it could be a Charactermancer issue with the SRD data being fed into it.