Vampire BW Deck

are you planning to FNM/tournaments?  do you know about formats (IE: standard, modern, legacy) if so which one will you be playing?

It looks like your main goal based on cards is to drain your opponents life by abilities, not by doing damage per say. Blood baron is designed to work best if you are gaining life quickly. Most of your cards reduce your opponents life but do not increase yours. There are a decent number of cards in your hand that do boost your life total but they will take some time to get going, and kick you up to 30 life. I would focus on either life gain or your opponents life reduction instead of both.

I see you have 3 Asphyxiate in your inventory its a good guard to use to cut down your opponents creatures. Liturgy of blood and Sip of Hemlock cost quite a bit of mana to cast. Asphyxiate only costs 3. I would replace them with Asphyxiate and Bile Blight.

Bile blight is also a very nice card if your opponent has multiples of the same creature out and is not expensive to cast.

You have 2 Doom Blades as well which can be handy in a pinch as well against other color decks or multicolor decks. I would at least sideboard them.
(Sideboard is a set of 15 cards you can swap out between games.) Devour flesh gives your opponent life, Doom Blade does not.

Duress is a great way to restrict your opponents casting as well. Possibly consider switching this in also.

Maybe swap out a Blood Bairn and Eater of Hope for a pair of Deathgaze cockatrice Deathtouch fliers are nice for blocking or attacking.

Just a few suggestions I am no expert by any means but I think some of the cards I mentioned could be useful. Also I am always told to focus on the theme and try to build on that, if you want to gain life focus on creatures and spells that gain you life, however gaining life generally does not win you games, if they have a destroy target creature card that Blood baron can disappear very quickly. You need to be able to dish out the damage as well. I would focus on getting creatures out quickly and putting a hurt on your opponent, instead of focusing the entire build on a single card. You have plenty of sorcery and enchantments as well to help reduce your opponents life.