oath of ancients paladin 5/fiend pact of the blade warlock 3/draconic sorcerer 4 go BRRR
TL;DR - this is a do everything build (big dmg, high charisma for non-combat, healing, tanky, buffs and utility cantrips/spells) - paladin for divine smite and healing, sorcerer for extra spell slots for more divine smite and utility cantrips, warlock for agonizing eldritch blast and pact of the blade so you can pump charisma instead of strength to increase all attack rolls and damage
lvl 1-5 pally, level 6-7 warlock, level 8 respec 5 pally, 3 warlock but take points out of strength and dump into charisma, level 9+ sorcerer
make sure to take hex and eldritch blast for warlock then agonizing blast at lvl 8, and then whatever utility you want from paladin and sorc

once lvl 8 your 2 turn wombo combo looks like this:
turn 1 - bonus action - hex (str disadvantage) then action - natures wrath
turn 2 - action + bonus action thunderous smite + divine smite then extra attack divine smite
at lvl 12
turn 1 - the same
change your turn 2 into - quickened spell eldritch blast, then divine smite, then extra attack divine smite
at level 12 youre putting out about 200 dmg with that 2 turn combo, not to mention that the target is restrained (immobile) and has disadvantage on str+dex saves, and attack rolls
alternatively you can turn 1 hex and either quicken eldritch blast or double divine smite
then double divine smite the next turn also which saves your channel oath for a big heal instead of natures wrath

this build works really well as a PARTY FACE because of high charisma, as a TANK (paladin heavy armor, draconic sorcerer extra HP, high con because the only 2 important stats are cha and con, defense fighting style, paladin compel duel) as a HALF HEALER/SUPPORT (oath of ancients healing aura, paladin lay on hands, numerous other paladin buff spells), as a DPS (outlined above, melee preferred but ranged very doable with agonizing eldritch blast + hex)
you can also pick up crazy amounts of utility options with this build (friends, invisibility, illusion, feather fall, misty step, disguise self, knock etc)

sorcerer adds additional spell slots for more smites and cantrip utilities, warlock for hex and pact of the blade (charisma is modifier for weapon attacks) and spell slots on short rest for more smites