Later in the play, after Romeo and Juliet have married and spent an evening together presumably, Lady Capulet reveals AGAIN to Juliet that Lord Capulet would have her marry Paris. This occurs in Act III. Lord Capulet changed his mind about hoping Juliet will marry Paris. Instead of needing her consent, since Tybalt is dead, Capulet decides Juliet is ready to marry because it will make her feel better.
Capulet knows nothing about her relationship with Romeo and therefore sets up this marriage and expects Juliet to be cheerful about it. After talking with Lady Capulet, Juliet realizes she is being pushed into marrying Paris. This bums her out.
Another piece of news you might be referring to is Tybalt's death.
Even Juliet's own father is unenthused about the idea of the County Paris being a good match for his daughter, so we should not be surprised at the dim view the hot-headed passionate young Juliet takes of this news. Paris is referred to in grey, monchrome and dusty terms elsewhere in the play. The similarity Lady Capulet sees in his face being similar to a book, so urging her daughter to look favourably on the volume of his face is rather uninspiring too - I'm sure Juliet is looking for something much more exciting and refreshing than a few dusty pages in her first sweetheart. She finds this new excitement in Romeo, whose youthful impulsiveness is a far cry from staid, conventional old County Paris!
You will be more certain of getting the right answer if you give us more information -- such as what part of the play the question is about.
I am assuming that your question refers to what happens in Act I, Scene 3. In that scene, Lady Capulet, who is Juliet's mother, comes to give her some news. After some comical back and forth between Lady Capulet and Juliet's nurse, Lady Capulet is able to tell Juliet what she has come for.
The news she brings is about marriage. She has come to tell Juliet that Paris wants to marry her.
She tells Juliet that Paris will be at the feast that night and Juliet can check him out. Little does she know that Juliet will fall in love with someone else at the feast...