Visiting Ireland (Dublin)

Good Evening All!!!
I Have one familiar living in Dublin as a student, and i would like to visit him on the beginning of May, I've decided to stay for 2 weeks.
The reason for the visit is that I'm going to work in the Caribbean in a couple of weeks and planing to stay over there for a little while, and me and my cousin are very close (1 week of birth difference). My question is: I'm Brazilian and at the moment i'm in Poland with my fiance, is there any special requirements to don't have any problem with immigration? I'm traveling with round trip (Poland - Dublin / Dublin -Poland) tickets and i can provide resources (money) for my trip.

Sorry about the long text, but i want to make sure that everything will be fine.
Thanks a lot in advance.

Regards