I can't point to any monologues for you specifically but if you really want to pursue it then the best place to start is at the beginning. There's no point in panicking, just visit libraries or ask drama teachers at your school for contemporary (modern) plays that suit you.
Big no-nos are doing monologues for characters who are difficult to imagine you playing for audiences.
Don't try any accents different from your own, if you can do accents that's great but panels want to hear you, not an American - unless you are American that is.
You also have to be willing to put yourself on the frontline and face any result with thick skin. Don't let anything affect you on a personal level.
When you read some plays and find a monologue, try and find the emotion you feel from it and don't use the ideas of actresses who have played the role as you want to be different not similar. That being said, choose monologues and plays that aren't extremely common. A friend I work with told me that 'if you pick a monologue that has been acted by someone popular you'll get contrasted to how they played it and they'll think of how you compare to said actress.' Be original with your choice. It doesn't have to be a needle in a haystack, but it shouldn't be something a lot of people might try and perform (like actors/tresses who do Romeo & Juliet monologues CRINGE).