Hii Gargi!

GU ART is the MSC level entrance examination conducted by Goa University. Talking about the sample papers, it would be better if you find some books for the same. You may get some samples on the respective official website. It's quite difficult to find sample papers like that. I would suggest you to prepare in such a way that you know everything which could be possibly asked. Revise everything which you studied in 3 years of your graduation and mostly in 3rd year. Keep in mind all the important concepts and you can do well. Hope this helps.

Good luck!