Question: The book is fairly new, at most 4 years and it's the start of a series.
I know vampires were involved and that the bookstore was open at night but
that's about it.

Answer: 
*[Night Owls](https://www.goodreads.com/book/show/18281997-night-owls)* by Lauren M. Roy

[![Book cover](https://i.stack.imgur.com/H5S6B.jpg)](https://i.stack.imgur.com/H5S6B.jpg)

> 
> *Night Owls **book store** is the one spot on campus **open late** enough to help out even the most practiced slacker. The employees’ penchant for fighting the evil creatures of the night is just a perk…*
> 
> 
> Valerie McTeague’s business model is simple: provide the students of Edgewood College with a late-night study haven and stay as far away from the underworld conflicts of her vampire brethren as possible. She’s lived that life, and the price she paid was far too high to ever want to return.
> 
> 
> Elly Garrett hasn’t known any life except that of fighting the supernatural werewolf-like beings known as Creeps or Jackals. But she always had her mentor and foster father by her side—until he gave his life protecting a book that the Creeps desperately want to get their hands on.
> 
> 
> When the book gets stashed at Night Owls for safe keeping, those Val holds nearest and dearest are put in mortal peril. Now Val and Elly will have to team up, along with a mismatched crew of humans, **vampires**, and lesbian succubi, to stop the Jackals from getting their claws on the book and unleashing unnamed horrors…
> 
> 
> 

It was released in 2014 and has been stated to be part of a series with *[Grave Matters](http://Grave%20Matters)* released in 2015.
*[Hounded](https://www.goodreads.com/book/show/9533378-hounded?from_search=true&search_version=service)* the first book in the *Iron Druid Chronicles* by Kevin Hearne

[![Hounded by Kevin Hearne](https://i.stack.imgur.com/iSrgw.jpg)](https://www.goodreads.com/book/show/9533378-hounded?from_search=true&search_version=service)

> 
> Atticus O’Sullivan, last of the Druids, lives peacefully in Arizona,
>  running an **occult bookshop** and shape-shifting in his spare time to
>  hunt with his Irish wolfhound. His neighbors and customers think that
>  this handsome, tattooed Irish dude is about twenty-one years old—when
>  in actuality, he’s twenty-one centuries old. Not to mention: He draws
>  his power from the earth, possesses a sharp wit, and wields an even
>  sharper magical sword known as Fragarach, the Answerer.
> 
> 
> Unfortunately, a very angry Celtic god wants that sword, and he’s
>  hounded Atticus for centuries. Now the determined deity has tracked
>  him down, and Atticus will need all his power—plus the help of a
>  seductive goddess of death, **his vampire and werewolf team of
>  attorneys**, a bartender possessed by a Hindu witch, and some good
>  old-fashioned luck of the Irish—to kick some Celtic arse and deliver
>  himself from evil.
> 
> 
> 

Points where this matches the description:

* Occult bookstore in which he has a collection of rare magical books
* Main character is owner of said bookstore
* One of his attorneys is a vampire, "friend" and sparring partner
* First book in the series
* Published during the mentioned four year time frame (2011)

What may not fit:

* Open at night - I don't specifically remember the bookstore open at night, but several of the key scenes do occur at night.

Only one point that doesn't quite match, but seems to match on all other details.