In some fanfictions, they might initially dislike each other. Draco, with his pure - blood supremacist upbringing, could look down on Harry. For example, he might make snide remarks about Harry's lack of knowledge about the wizarding world. However, this early encounter could also lead to a different dynamic later at Hogwarts. Maybe Harry would be more prepared to face Draco's taunts because of this prior meeting.
Another possibility is that they meet and there's an immediate sense of rivalry. Even before Hogwarts, Draco might feel threatened by Harry's fame as 'The Boy Who Lived'. This could lead to a more intense and personal feud throughout their time at Hogwarts. Their early meeting could be the spark that ignites a long - standing enmity.