"beginning level" vs "beginning levels"

Hi all,

I have got more than one English grammar books on the bookshelf in my bedroom,
so I am thinking if I shall add a s after beginning level to make it a plural noun.
I am not sure which of the following sentences is better:

(1): I have got some English grammar books at beginning level.
(2): I have got some English grammar books at beginning levels.

Could you help please?

I have got some English grammar books at beginner(s) level.