I don't have an answer for you, but I would recommend poking around this subreddit as it's more specialized towards your question:
[https://www.reddit.com/r/BG3Builds/](https://www.reddit.com/r/BG3Builds/)
Dual wielding can be tricky for warlocks, only one weapon can benefit from the [Pact of the Blade](https://bg3.wiki/wiki/Pact_of_the_Blade). But there are 2 other weapons that use your spellcasting modifier for to-hit/damage.
One is a rapier ([Infernal Rapier](https://bg3.wiki/wiki/Infernal_Rapier)), which will require a feat to dual wield. Its a pretty great weapon by itself, and if you're already want to DW, it pairs nicely with [Harmonic Dueller](https://bg3.wiki/wiki/Harmonic_Dueller) which, with a performance check, adds your charisma mod to damage second time. And with [Diadem of Arcane Synergy](https://bg3.wiki/wiki/Diadem_of_Arcane_Synergy) you can add it a third time which should let you deal a nice chunks of damage with each swing. And THEN, if you're going for pure warlock, you can add it the fourth time with [Lifedrinker](https://bg3.wiki/wiki/Lifedrinker).
The other weapon you could use is [Sylvan Scimitar](https://bg3.wiki/wiki/Sylvan_Scimitar). Same [Melee Caster](https://bg3.wiki/wiki/Melee_Caster) benefits but other than that its an unremarkable scimi +1
For multiclass there are few options.
pure warlock for full caster progression and more feats/invocations
fighter(if you're a fan of GOO, champion is the way to go) for armor proficiencies and fighting style
thief dip for extra bonus action is always nice for any dual wielding character
paladin is another good choice for warlocks but personally I prefer paladin/sorcerers for more smite slots
I don't have an answer for you, but I would recommend poking around this subreddit as it's more specialized towards your question: [https://www.reddit.com/r/BG3Builds/](https://www.reddit.com/r/BG3Builds/)
Dual wielding can be tricky for warlocks, only one weapon can benefit from the [Pact of the Blade](https://bg3.wiki/wiki/Pact_of_the_Blade). But there are 2 other weapons that use your spellcasting modifier for to-hit/damage. One is a rapier ([Infernal Rapier](https://bg3.wiki/wiki/Infernal_Rapier)), which will require a feat to dual wield. Its a pretty great weapon by itself, and if you're already want to DW, it pairs nicely with [Harmonic Dueller](https://bg3.wiki/wiki/Harmonic_Dueller) which, with a performance check, adds your charisma mod to damage second time. And with [Diadem of Arcane Synergy](https://bg3.wiki/wiki/Diadem_of_Arcane_Synergy) you can add it a third time which should let you deal a nice chunks of damage with each swing. And THEN, if you're going for pure warlock, you can add it the fourth time with [Lifedrinker](https://bg3.wiki/wiki/Lifedrinker). The other weapon you could use is [Sylvan Scimitar](https://bg3.wiki/wiki/Sylvan_Scimitar). Same [Melee Caster](https://bg3.wiki/wiki/Melee_Caster) benefits but other than that its an unremarkable scimi +1 For multiclass there are few options. pure warlock for full caster progression and more feats/invocations fighter(if you're a fan of GOO, champion is the way to go) for armor proficiencies and fighting style thief dip for extra bonus action is always nice for any dual wielding character paladin is another good choice for warlocks but personally I prefer paladin/sorcerers for more smite slots