You have draconic ancestry. Course one type of dragon from the Draconic Ancestry table. Your breath Weapon is determined by the dragon type, we shown in the table.

Brass- Fire- 5 by 30ft line- Dex save

Bronze- Lightning- 5 by 30ft line- Dex save

Copper- Acid- 5 by 30ft line- Dex save

Gold- Fire- 15ft cone- Dex save

Silver- Cold- 15ft cone- Con save

You can use your action to exhale destructive energy. Your draconic ancestry determines the size, shape, and damage type of the exhalation.When you use your breath weapon, each creature in the area of the exhalation must make a saving throw, the type of which is determined by your draconic ancestry. The DC for this saving throw equals 8 + your Constitution modifier + your proficiency bonus. A creature takes 2d6 damage on a failed save, and half as much damage on a successful one. The damage increases to 3d6 at 6th level, 4d6 at 11th level, and 5d6 at 16th level. After you use your breath weapon, you can’t use it again until you complete a short or long rest.

As an action, you can change your appearance and your voice. You determine the specifics of the changes, including your coloration, hair length, and sex. You can also adjust your height and weight, but not so much that your size changes. You can make yourself appear as a member of another race, though none of your game statistics change. You can't duplicate into a creature you've never seen, and you must adopt a firm that has the same basic arrangement of limbs that you have. Your clothing and equipment aren't changed by this trait. You stay in the new form until you use an action to revert to your true form or until you die.