Sounds like an Oath of Vengeance Paladin and Dragonic Sorcerer to me. They both use charisma as their spells, which is also the stat you need for Intimidation checks when you're in conversations
If you plan on being the only Character on the frontline Paladin 5 Sorceror 7 is a great option. If you are planning to have an ally up there with you I would do 6 and 6 instead so that you can give your ally the saving throw bonus from your aura. Either way nets you the same amount of spell slots. Though we aren't sure yet how Larian is reworking access to spells, even if you don't get the 5th level Sorcerer spells, you can just use the slots for your Paladin smites. Crushing you enemies with 'Radiant' damage, is often the alternate 'Fire' type of damage that religious classes get. Between the Paladin and Sorcerer, you'll be doing plenty damage of both types.
Definitely start as a Paladin with ability scores like the below if you want to punch as hard as you hurl fireballs. If one is more important than the other, you swap the 16/14 to Constitution to survive a little better.
STR 16
DEX 10
CON 14
IINT 8
WIS 10
CHA 16
If this sounds like something you'd like I can put together a build for you. We'd just want to identify if you would rather do first: attack twice or throw fireballs. And if you would rather be defensive up close or swing a big weapon.
