A a bonus action after making an attack action you can blast a line of your dragon ancestry type  the line is 10ft long and 5ft wide. All creatures in the line must make a dex save equal to your con on a fail they take 1d10plus your con or half on save  damage of your ancestry type if they fail you  can spend one extra use to do one extra feature according to your dragon type.

Lighting: They are pushed back 5ft 

Fire: They take a extra 1d6 fire next turn

Acid: Their movement speed is reduced by 10ft for one turn . 

Posion: Their next attack has disadvantage. 

Necrotic: they cant regain hp till the end of their next turn.You can use this 3 times per long rest. 

Your lineage stems from a dragon progenitor. Choose the kind of dragon from the Draconic Ancestors table. Your choice affects your Breath Weapon and Damage Resistance traits as well as your appearance.

You have Darkvision with a range of 60 feet.

When you make a melee or ranged weapon attack you can roll one hit dice add your con and do that much damage of your dragon ancestry type.