Ok so i have a limited number of spells per day (depending the spell).
No the number of spell slots per spelllevel depends upon your spellcaster level.
Every Bard, Cleric, Druid, Sorcerer and Wizard level counts as one spellcaster level.
Every second Paladin and Ranger level counts as one spellcaster level.
And every third Eldritch Knight (Fighter subclass) or Arcane Trickster (Rogue subclass) level countrs as one spellcaster level.
But then its always the same list:
Caster Level 1: 2 Level 1 Slots
Caster Level 2: 3 Level 1 Slots
Caster Level 3: 4 Level 1 Slots, 2 Level 2 Slots
Caster Level 4: 4 Level 1 Slots, 3 Level 2 Slots
Caster Level 5: 4 Level 1 Slots, 3 Level 2 Slots, 2 Level 3 Slots
Caster Level 6: 4 Level 1 Slots, 3 Level 2 Slots, 3 Level 3 Slots
Caster Level 7: 4 Level 1 Slots, 3 Level 2 Slots, 3 Level 3 Slots, 1 Level 4 Slot
Caster Level 8: 4 Level 1 Slots, 3 Level 2 Slots, 3 Level 3 Slots, 2 Level 4 Slots
Caster Level 9: 4 Level 1 Slots, 3 Level 2 Slots, 3 Level 3 Slots, 3 Level 4 Slots, 1 Level 5 Slot
Caster Level 10: 4 Level 1 Slots, 3 Level 2 Slots, 3 Level 3 Slots, 3 Level 4 Slots, 2 Level 5 Slot
Caster Level 11: 4 Level 1 Slots, 3 Level 2 Slots, 3 Level 3 Slots, 3 Level 4 Slots, 2 Level 5 Slot, 1 Level 6 Slot
Caster Level 12: (No Change)
Obviously a pure Paladin or Ranger will only reach spellcaster level 6, and an Eldritch Knight or Arcane Trickster wont get higher than level 4.
In what these classes differ is how they prepare spells, i.e. on what spells specifically they can spend these slots.
Also, Warlock is not within this logic, they are treated completlely separately.
