Your curse grants you both strong supernatural powers, and at the same time, several unnatural weaknesses. 

Accursed Courtesy 

You are unable to enter a homestead unless you are explicitly invited. This does not apply to non-domestic places like a dungeon, crypt, castle, or stronghold, but does apply to specific places like a bedroom.

Non-Reflective

For some reason you do not appear in mirrors. This isn't necessarily a weakness, but can be used to give you away. 

Stake Hearted 

Upon being staked through the heart with a specifically wooden stake, you are immediately paralyzed until it is removed, or you manage to conquer the effect with a DC 20 strength saving throw. If this occurs whenever you are at 0 HP, your body bursts into flames, you disintegrate, and your soul passes on unless a dark ritual is performed on your ashes and bones to resurrect you.  

Sunlight Sensitivity 

Your accursed blood is highly vulnerable to the sun and all things light. When in bright sunlight you suffer disadvantage on attack rolls and perception, unless you are wearing some sort of shaded eye protection, or something is shading you from direct sunlight. Additionally you are vulnerable to radiant damage. 

Weaknesses and Compulsions 

Several things, from elemental to mythological, can damage or hinder you.

• Your body is both vulnerable to fire and water. When starting your turn in any standing body of water that is up to your knees in depth, you take 1d10 acid damage and are compelled to flee the water as fast as possible. You also have a strong aversion to crossing a bridge or boarding a ship. Additionally, you have a strong aversion to open fires, and when taking fire damage of any sort, magical or natural, you take an additional 1d8 fire damage. 
• Holy water has an especially powerful effect on you. Upon being splashed, you take 3d8 acid damage. 
• Garlic and lines of salt have a supernatural effect on you. When encountering either, make a DC 15 wisdom saving throw. If you succeed, you can safely cross the salt barrier or be unaffected by the garlic. If you fail, you are unable to force yourself to cross or disturb the salt, or become fearful of the garlic and must avoid touching it, taking 1d4 burning damage when coming in contact with it. 
• Silver burns your undead flesh much like the sun. You are vulnerable to any weapons made with silver. 
• Symbols of Good aligned gods, particularly ones associated the Sun, or a cross, are highly effective in deterring you. A DC 20 Wisdom saving throw is required to resist their influence. Otherwise, you become fearful and must flee the object, and upon making contact with it take 3d8 damage. 

You can attempt to bite someone and drain their blood. Make an attack roll, adding your strength modifier to bite your victim and drain their blood. This does 1d6 damage, half of which, rounded down, you receive as HP. If a victim is incapacitated and you attempt this bite you automatically succeed, and can choose to kill your victim, at which point you receive 2d10 HP. Alternatively, you can attempt to infect your victim with vampirism and convert them into a vampire, though this is up to the DM's discretion. 

The body of a vampire is immune to death of the standard variety. If you are reduced to 0 HP and fail your death saving throws, you are not traditionally dead, but rather totally unconscious until the next night at which point you reanimate once more. However, your undead state is both beneficial and detrimental. You cannot be healed by traditional spells such as Cure Wounds or Healing Word. 

Only through drinking blood through your bite, or drinking it externally, will you regain any hitpoints. For every "cup" worth of blood ingested, you regain 1d6 hit points. You can additionally regain hit points in a short or long rest by going into a hibernation state, typically inside a protective coffin of some sort to keep you safe.

If you are rendered unconscious by dropping to 0 HP, and then staked in the heart, your body will combust into flames leaving behind nothing but a pile of black ash and your charred skeleton. By combining all of your bones, at least 1 handful of your black ash, an entire bodies worth of blood from an innocent person, and a black pearl worth 150gp in a large bowl made of black clay inscribed with necromantic runes, while performing a demonic ritual you can be resurrected. Your soul will be returned, by force, from the afterlife. Your body will reanimate in a flash of lightning in the same condition you were prior to death, with half of your hit points and none of your equipment. 

Your Intelligence score increases by 1, and your Charisma score increases by 2.

You are undead, and therefore functionally immortal. You will remain whatever age you were upon being bitten, forever. Spells or magic to change your age do not work. 

Vampires are inherently known to be evil due to their dark nature and the fact they must consume the blood of the living. Many are known to resist the urge to turn towards darkness in favor of being good, though most are consumed by their hunger.

Vampires are typically human or humanoid creatures. Your size is Medium.

Your base walking speed is 30 feet.

Thanks to your curse, you have superior vision in dark and dim conditions. You can see in dim light within 60 feet of you as if it were bright light, and in darkness as if it were dim light. You can’t discern color in darkness, only shades of gray.

You have resistance to cold damage and immunity to necrotic damage. 

You know the thaumaturgy and chill touch cantrip. When you reach 3rd level, you can cast the charm person and expeditious retreat spells as 2nd-level spells once with this trait and regain the ability to do so when you finish a long rest. When you reach 5th level, you can cast the darkness and misty step spells once with this trait and regain the ability to do so when you finish a long rest. Charisma is your spellcasting ability for these spells.

You can speak, read, and write Common and Infernal.