speaker's thoughts on his futility on getting a date
...what do guys with lots of girls normally do?
not quite sure how to read 彼女が複数人いるような男, literally a guy that is similar to many girls?
the kind of guy who has many girlfriends
AようなB means "a B that is like A," which in English we could also translate as "an A kind of B."
Recall also that いる, like ある can mean "to have". 彼女がいる = I have a girlfriend.