Your draconic magic has an affinity with a damage type associated with dragons. Choose one of those types: Acid, Cold, Fire, Lightning, or Poison.
You have Resistance to that damage type, and when you cast a spell that deals damage of that type, you can add your Charisma modifier to one damage roll of that spell.
RollQuest ships the D&D 2024 SRD as a content pack, on a 5e character sheet that does the maths - roll from the sheet and let the numbers work themselves out. Free to start.