Your base walking speed is 25 feet and you have a 30 feet swim speed

You can breathe air and water.

Young dragonborn grow quickly. They walk hours after hatching, attain the size and development of a 10-year-old human child by the age of 3, and reach adulthood by 15. They live to be around 80.

You can use your action to exhale destructive steam. Each creature in a 15-foot cone in front of you must make a Constitution saving throw. Each creature in a 15-foot cone in front of you must make a Constitution saving throw A creature takes 2d8 fire damage on a failed save, and half as much damage on a successful one. The damage increases to 3d8 at 6th level, 4d8 at 11th, and 5d8 at 16th. Being underwater doesn't grant resistance against this damage. After using your breath weapon a number of times equal to your proficiency bonus, regain all expended uses after completing a long rest.

Dragonborn are taller and heavier than humans, standing well over 6 feet tall and averaging almost 250 pounds. Your size is Medium.

You have resistance to fire damage and are immune to the effect of water pressure found in the depths.

When you're not wearing armor, your AC is equal to 15+ half your Dexterity Modifier (rounded down).

You can speak, read, and write Common and Draconic. Draconic is thought to be one of the oldest languages and is often used in the study of magic. The language sounds harsh to most other creatures and includes numerous hard consonants and sibilants.