What does 个 mean in 感觉这像**个**文盲一样
文盲 (illiterate) can be a noun on its own, no need to add 的人


  illiterate 
  
  
  an illiterate person (noun)
  


"我们四个人(之中)没有一个" = "no one (among) the four of us"

"会说西班牙语"=  "can speak Spanish"


  "感觉这像个文盲一样。" = "Felt like an illiterate"
  
  There are many problems with this sentence, Since the subject is not mentioned, it can either be "all four of us" or "I". 



If the subject was "all four of us" then the singular "一个文盲" (an illiterate) would have to be changed to "一群文盲" (a group of illiterates)
If the subject was "I", it should not be omitted because people would get confused  by "我们四个" (we four) at the beginning. 
"我感觉像个文盲一样" (I felt like an illiterate) lacks an object after the verb, therefore we should add 

(1) "自己" (myself) as the object to clarify "I myself" is the object that I felt like an illiterate -- The sentence would then become "我感觉自己像个文盲一样"

(2) "我们" (we) as the object to clarify "we four" is the object that I felt like a group of illiterates-- The sentence would then become "我感觉我们像群文盲一样"


We can replace 感觉(feel) with 觉得(feel), because  感觉 can also be a noun, but 觉得 is clearly a verb 

The sentence should then become "我觉得自己像个文盲一样" (I felt I was like an illiterate) or "我觉得我们像群文盲一样" (I felt we were like a group of illiterates)